PHYSIOLOGY NEWS

winter 2007 | number 69

In this issue Teaching ethics to physiology students How to get good science Bioscience learned societies – not fit for purpose? Images of Manchester

Manchester Focused Meeting Cardiac electrophysiology: with a special celebration of the centenary of the discovery of the sinoatrial and atrioventricular nodes

5–6 September 2007 PHYSIOLOGY NEWS Editorial 3 Meetings Renal cortex: physiological basis of glomerular and tubular The Society’s dog. ‘Rudolf Magnus gave me to Charles diseases Dave Bates, David Sheppard 4 Sherrington, who gave me to Young Physiologists Bursary Scheme awards Nicola Trim, Henry Dale, who gave me to The Clare Gladding, Ciara Doran, Caroline Cros, Michael Morgan, 5 Physiological Society in October Lai-Ming Yung 1942’ Young Life Scientists’ Symposium at LifeSciences2007 Susan Chalmers, Marnie Olson, Patrick Howorth, Ahmed Khweir 7 Published quarterly by The Physiological Society Setting the pace Otto Hutter 8 Living History Contributions and queries Senior Publications Executive What can clinical medicine give back to physiology? 10 Linda Rimmer John Dickinson The Physiological Society Publications Office Soapbox P O Box 502, Cambridge CB1 0AL, UK How to get good science David Colquhoun 12 Features Tel: +44 (0)1223 400180 Fax: +44 (0)1223 246858 From lamprey swimming to human stepping: evolutionary Email: [email protected] conservation of longitudinally-propagated spinal activity 15 Web site: http://www.physoc.org Mélanie Falgairolle, Jean-René Cazalets Brain rhythms, synaptic plasticity and sleep Daniel Ulrich 18 Magazine Editorial Board Tropomyosin mutations responsible for muscle weakness in Editor inherited skeletal muscle diseases Julien Ochala, Anders 20 Austin Elliott Oldfors, Lars Larsson University of Manchester, Manchester, UK Muscle’s silent sensors Uwe Proske 22 Members Patricia de Winter The pattern of intracellular Ca2+ signal matters in epithelial University College London, London, UK secretion Seung-Ryoung Jung, Toan Nguyen, Bertil Hill, 25 Duk-Su Koh Sarah Hall β Cardiff University, Cardiff, UK -adrenergic receptor desensitisation – a mechanism for post­ exercise reductions in cardiac function Rob Shave, Keith 27 Munir Hussain George, Emma Hart University of Liverpooll, Liverpool, UK ATP synthesis during ischaemic muscle contractions John Lee Ian Lanza, Jane Kent-Braun 30 Rotherham General Hospital, Rotherham, UK Colonic elongation activates an intrinsic reflex that underlies Thelma Lovick slow transit and accommodation Terence Smith, Eamonn 33 University of Birmingham, Birmingham, UK Dickson, Grant Hennig, Peter Bayguinov, Nick Spencer Bill Winlow An integrative approach to control of oxidative phosphory­ Chameleon Communications International, London/ University of Liverpool, Liverpool, UK lation during exercise Brendon Gurd, George Heigenhauser, 36 Donald Paterson, John Kowalchuk

Foreign Correspondents Contribution of myoglobin facilitated O2 diffusion in respiring John Hanrahan tissue Ping Chang Lin, Ulrike Kreutzer, Thomas Jue 39 McGill University, Montreal, Canada Education John Morley Teaching ethics to physiology students Dave Lewis 41 University of Western Sydney, NSW, Australia Letter to the Editor 42 © 2007 The Physiological Society The Society’s journals ISSN 1476-7996 Experimental Physiology 43 The Journal of Physiology 43 The Physiological Society is registered in England as Memorable Members a company limited by guarantee: No 323575. Registered office: PO Box 11319, London WC1X 8WQ Joseph Francis Donegan Ian Roddie 45 Registered Charity: No 211585. Benevolent Fund 46 Parliamentary and Scientific Committee Printed by The Lavenham Press Ltd Is dual funding fit for purpose? Liz Bell 47 Society News Scientific meeting calendar 2008 49 Introduction of registration fees Prem Kumar 50 Biosciences Federation Are bioscience learned societies ‘not fit for purpose’? Richard Dyer 51 Do learned societies behave like racing drivers? Mike Collis 52 Unbelievable! 53 Obituaries David Jordan Michael Gilbey, James Jones, Ida Llewellyn-Smith 54 Venetia Franglen Richard Naftalin 55 From the archives 56 EDITORIAL PN 3

It’s good to talk – and note that there are multiple ' Stick to what y ou know, and if definitions of either word, both you can’t, stick close to what is (carefully) popular and scientific – then you known' – might be a good rule of The Physiology News editorial slot can provoke a global storm of thumb. intermittently encourages denunciation, as James Watson scientists to get involved in public did recently. Physiology is perhaps fortunate discussions about science, not to touch often on areas as whether local or national. It is not my purpose here to directly contentious as race, debate what Watson said, or is genetics and IQ. But it still offers However, there are downsides to said to have said. Much has been opportunities for foot-in-mouth this. One is the dilemma when written by people far better stuff. Physiologists in the public you get asked to comment on placed than I to comment (see eye typically do stick close to their something you don’t know much e.g. [1]). What we can say is that own ground: they can frequently about. if, as seems likely, we have seen a be found commenting on issues great scientist’s exit from the around animal experimentation, The safe option on this is, first, to public arena, it is a sad way for and sometimes about brain admit you don’t know much him to bow out. Most of us, I am scanning, or stem cells, or IVF, or about it, and then second, fall sure, hope the fall-out will not even the scientific basis of drug back on generalities and overshadow Watson’s lifetime of policy, while they are less likely to consensus, or on things that distinguished achievements in be found offering their views on couldn’t possibly be objected to science. whether science disproves the but bear a re-statement. In other existence of the soul. words, stick to what you can say, What I do want to do here is give useful information, and avoid comment on the limits of I hope Watson’s fate will not scare ranting. scientific authority, and where this eminent scientists off engaging in interfaces with the continued public debates. More than ever, The danger comes if you engage need for scientists to speak up in we need them out there the mouth before the brain, speak public. explaining, and clarifying, and – off the cuff and give unvarnished perhaps most important of all – personal opinions without making As a thoroughly ordinary scientific correcting common and even clear they are strictly opinions. practitioner I am in the fortunate dangerous misconceptions. Just position that I will never be asked the weekend I wrote this, Mike The more famous and eminent by a journalist with a tape­ Rennie was chiding The Guardian the scientist, the greater the recorder running for my thoughts for multiple inaccuracies in their danger. For the run-of-the-mill on global warming, the nature of coverage of 'synthetic biology' scientist speaking in a local forum, consciousness, or when an (3). Long may people like him schools workshop, town meeting, embryo becomes a human being. continue to speak out. But Café Scientifique, or whatever, you But some scientists do get asked equally, long may they take care are unlikely to come too much of these questions, and it is then that what they say. a cropper if you do say something they have to choose their words daft. You will usually be able to carefully. Sadly, it is common in One of the more measured online correct and clarify what you said, places promoting bad science to commentaries on Watson’s or even take back things you did find quotations from famous downfall on the Wired Science not mean. scientists speaking about things blog (4) quoted the American that they should have been wise author Marilynne Robinson: At the other end of the scale, if enough to keep quiet about. The ' There is nothing harder than you are a world-famous scientist statements made by Kary Mullis, knowing what it is you don' t and Nobel Laureate facing a room of PCR fame, about HIV and AIDS know.' As scientists, we forget this at our peril. full of journalists, and touch in his autobiography (2) are one unhappily on a subject as well-known example, but there Austin Elliott explosive as race and intelligence are others.

1 http://www.timesonline.co.uk/tol/comment/columnists/guest_contributors/article2702762.ece 2 Mullis, Kary. 1998. Dancing Naked in the Mind Field. New York: Vintage Books. 3 http://www.guardian.co.uk/comment/story/0,,2199474,00.html 4 http://blog.wired.com/wiredscience/james_watson/index.html

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Renal cortex: cells of the renal cortex, in particular the role of the glomerular and tubular physiological basis of epithelium and endothelium in regulating salt and water balance in glomerular and health and disease. An uninterrupted tubular diseases layer of epithelial cells line the nephron, from podocytes in The Department of Physiology and glomeruli to intercalated and Pharmacology at the University of principal cells in the collecting duct. Bristol is delighted to host its first Ultrastructural and molecular Physiological Society Focused differences between these cell types Meeting on 17 and 18 December. reflect the vast differences they make The Department was formed on to the conversion of ultrafiltrate to 1 August by the merger of the urine. Recent advances in animal existing Departments of Physiology models of human disease that inform and Pharmacology, which had normal function, cell-specific complementary research interests inducible transgenic models that and expertise, focused on highlight the role of individual cardiovascular research, cell biology molecules in normal adult physiology, and neuroscience, each pursued in a cell biology techniques that provide collaborative, inter-disciplinary conditionally immortalised cell types research environment. The merger of precise origin and molecular has generated critical mass in each of characterisation of ion channels and Bristol skyline looking towards the Will Memorial Building and science buildings these research areas, and increased transporters that underpin normal (Zhe Xu, top); muscle physiology in the expertise and facilities available. physiology and pathophysiology have action (Hamish Roots, above); the The Department now comprises 35 provided a wealth of new models of physiology laboratory (Dave Bates, academic staff and six independent renal cell and nephron behaviour. below left). research fellows, as well as excellent Investigation of individual specialised support staff; it retains Bristol’s epithelial cell types in the nephron information between physiologists traditional strengths in in vivo and with these tools has generated an investigating renal function and systems physiology, but genetic, explosion in our understanding of clinicians treating renal dysfunction. molecular and cellular approaches are renal epithelial cell function. This also widely used in work within the meeting will highlight this wealth of Bristol has strong interests in renal Department, which spans from the new knowledge, focusing on research, especially glomerular gene to the whole animal and molecular aspects of ion and solute microvascular and renal epithelial translation to the clinic. transport by cell types throughout physiology. This work is conducted the nephron, revealing how within the Department of Physiology This Physiological Society Focused techniques used to advance our and Pharmacology, the Academic Meeting on renal cortical physiology understanding of the behaviour of Renal Unit at Southmead Hospital in in health and disease is organised one nephron cell type are applicable the Faculty of Medicine and Dentistry jointly by the Renal Physiology and to neighbouring cell types. The at the University and the Department Epithelial & Membrane Transport function of epithelial cell types of Biochemistry. Special Interest Groups and throughout the nephron, and generously supported by Kidney additional cell types such as We look forward to welcoming you to Research UK and the Renal mesangial and glomerular endothelial the meeting, with 10 invited speakers Association. The focus of the cells, will be discussed. We expect from Europe and North America, 16 meeting is the regulation of renal the meeting to provide a valuable oral communications selected from function by epithelial and associated forum for the exchange of submitted abstracts and an extensive poster session. The Society dinner will be held in the first class dining salon aboard the ss Great Britain, Isambard Kingdom Brunel’s masterpiece of engineering refurbished in its original style from the mid 19th century. We promise you excellent science, rigorous discussion and and entertaining time. Dave Bates & David Sheppard Department of Physiology, University of Bristol, UK

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The Young Physiologists Bursary Scheme (YPBS) aims to encourage young physiologists to attend their first scientific meeting of The Society without the need to present an abstract. Twenty two awards were made to support young physiologists’ attendance at LifeSciences2007 in Glasgow in July and here’s what some of them had to say about it …

When I heard about Hotel, which was conveniently names, hear others’ findings on LifeSciences2007 it seemed like the adjoined to the SECC where the subjects you are researching, chat perfect way to get an insight into conference took place. The next over coffee about exciting new many of my research fields all at once morning we registered for the information you had just discovered – a bit like Christmas for scientists! conference and were handed and to feel part of such a large As I was fairly new in my lab, I was badges, pens, notebooks and a fully ‘ team’ of people with the same not immediately invited to the abstracted guide to the lectures. We interests and enthusiasm. conference, but fortunately my got to work planning where we supervisor told me of the Young needed to be that day and each set In between lectures and lunch, Physiologists Bursary Scheme from off to our lecture of interest. This was opportunities arose to peruse the The Physiological Society for no easy decision, however, as much high quality posters submitted by students attending their first time was spent deliberating which to students and to absorb yet more conference and not presenting. I choose when two beneficial lectures knowledge. The trade exhibition was applied immediately and was were scheduled at the same time, or useful too, with many scientific granted the full bursary of £250 to one after another at opposite ends of companies available to give advice cover conference registration fees, the building! I must have looked and product information (not travel, up to two nights rather amusing running between forgetting freebies) to anyone who accommodation and, if budgeted, lecture theatres with my bag on my strolled around the stands. conference events. My lab subsidised back, and notebook and pen at the my accommodation and travel and, ready! But it was worth it; the The fun didn’t stop there … the being a bit of a socialite, I was subjects covered were varied, the social events should not be delighted to use the remaining number of speakers numerous and forgotten! Welcome drinks at the bursary on the conference gala lectures were well prepared, well Kelvingrove Art Gallery and Museum dinner and welcome drinks! timed and thoroughly interesting. I was a great way to get people even ventured to lectures outside my talking, whether it was about My lab group and I arrived in area of work because of their quirky science, the Scottish piper playing Glasgow on Sunday 8 July at the and curiosity-provoking titles and the bagpipes as guests mingled, or glass-fronted, towering Crown Plaza abstracts. It was great to put faces to the curious taxidermy display of

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‘amazing creatures’ on the first generation of scientists. I am highly The Physiological Society floor! It was a great opportunity for appreciative of being awarded the me to waffle on to people about my bursary to enable me to attend both Plenary Lecturers at research and see them wide-eyed these events. I certainly made the most LifeSciences2007 and intrigued rather than looking at of what the programme had to offer; it their shoe laces or yawning! was a very busy 4 days! I would definitely recommend other young The gala dinner on Wednesday was a scientists to take advantage of the more formal, extended version of the bursary scheme to attend future welcome reception, and after a events. tantalising three course dinner and short, humorous, yet rallying Clare Gladding speeches from members of each of Final year PhD student, Department the organising groups of the of Anatomy, University of Bristol, UK conference, the party began! The fantastic live band started to play, I found that I had ample time to and the wine provided with the meal wander through and talk at the was evidently required as a little poster sessions. The availability of ‘ Dutch courage’ to enable people to the abstracts at the venue ensured let their hair down and start flinging navigating through the posters was arms and legs around and swinging an easy undertaking. The talks aimed partners out of sequence to what at junior scientists were an excellent should have been an organised addition to the conference. As Scottish Ceilidh! Much fun was had someone who has not published yet, by all, whether you were the the talk on writing and publishing offending in question, or the wise papers was very helpful and who sat giggling at the mess of informative. It would be fantastic to ungainly, gyrating bodies on the see more of these kinds of tutorials dance floor. in the future.

All in all the conference was Ciara Doran extremely worthwhile and I look First year PhD student, Department forward to the next one. Much of Physiology, University College knowledge was acquired and shared Cork, Ireland by such an encouraging number of members from various science Notwithstanding the diverse symposia communities, giving myself, and presented by field leaders and the undoubtedly others, the passion and special plenary lectures, persistence to continue investigating LifeSciences2007 also displayed a huge this fascinating subject we call collection of posters. By alternating science. short talks given by postdocs with longer communications Nicola Trim given by leaders In the corresponding PhD student, Laboratory of field, it was easy to switch from one Molecular Signalling, Babraham session to another and a great Institute/University of Cambridge, opportunity to learn about other UK people's research. Displaying the same posters over 2 days allowed time to see A YPBS gave me the chance to attend and focus on each one. The different Tom Bolton (top) gave the Annual both LifeSciences2007 and to take part workshops and trade stands Review Prize Lecture Smooth muscle in the young physiologists' symposium emphasized the dynamic of this excitation; Michael Joyner (centre) held prior to it. This was a small meeting. Apart from the excellent gave the Michael de Burgh Daly meeting focusing on advances in science, the social events offered a Lecture A sympathetic view of the signalling. It enabled young scientists more informal way to meet and sympathetic nervous system and like me to share ideas and learn about discuss. human blood pressure regulation; exciting research developments in the and Denis Noble(above) gave the field. This introductory meeting was on Caroline Cros Paton Lecture Claude Bernard, the a smaller scale and facilitated PhD student, University of first systems biologist, and the future interactions amongst the younger Manchester, UK of physiology.

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The main things I came away with As is the case in most scientific were the need to immerse myself in research these days, the posters science more than I currently have presented at YLS2007 were not so been to understand my areas of much divided into areas based on interest, and the complexity of societal membership but more due signalling that has evolved, and its to an overall research theme. The importance in human biology. high quality of both the oral and poster presentations made it difficult Michael Morgan to choose the awardees for the BSc student in Medical Genetics, Young physiologists enjoy the welcome prizes. Each society presented an drinks reception at the Kelvingrove Art University of Huddersfield, UK award for both the best oral and Gallery and Museum – a great way to get poster presentation. The Biochemical people talking. It was my first time at an international Society awards were presented to scientific meeting. As a postgraduate Kathleen O’Hagan (University College Dublin) for oral presentation student from Hong Kong, this was a researchers. YLS2007 was an and Sanam Mustafa (University of tremendous personal achievement and overwhelming success! In Glasgow) for poster presentation; the meeting was a great opportunity attendance were over 160 registered The Physiological Society awards for me to broaden my horizons and delegates from all over the world were presented to Patrick Howorth enrich my knowledge, and so help me including delegates from Japan, (University of Bristol) for oral with the challenges in my career. For Australia, Canada, USA, Slovakia and presentation and Lydia Jimenez-Diaz me, the most impressive event on China. More locally there were (University College London) for Career Day was the Speed data delegates present from all regions of poster presentation; the British session, to which The the UK, including those from Pharmacological Society awards Physiological Society invited London, Oxford, Belfast, Plymouth, were presented to Grant Budas academics, clinical research officers, Leicester, Bristol, Glasgow, Dundee (Stanford University) for oral science teachers, and even editors of and Aberdeen. The theme of the presentation and Alexandra peer -reviewed journals. There was a symposium was Advances in Zahradnikova (Slovak Academy of friendly and relaxed environment for signalling and there were two poster Sciences) for poster presentation. An people to share past working sessions showcasing almost 100 overall YLS2007 prize was awarded experiences, so that participants learnt abstracts and 12 oral by Pfizer to Andrew McBride more about the possible career paths. communications highlighting (University of Dundee) for his poster selected research in the areas of entitled The glycogen binding Lai-Ming Yung neuronal, calcium, cardiovascular domain of the â–subunit of AMPK PhD Student, Department of and cellular signalling. There was functions as a sensor of glycogen Physiology, Chinese University of also a full social programme allowing quality. Hong Kong, China delegates to register and mingle at an evening reception prior to the Finally, we would like to thank our Young Life Scientists’ symposium and a post symposium sponsors, Institute of Pharmacy and dinner at Modern India restaurant Biomedical Sciences (SIPBS) Symposium at (generously sponsored by the University of Strathclyde, Institute of Universities of Strathclyde and Biomedical and Life Sciences (IBLS) LifeSciences2007 Glasgow respectively). University of Glasgow, Pfizer, The Young Life Scientists’ Stratech, AstraZeneca, Sigma-Aldrich Symposium (YLS2007) took place on Phil Hawkins (Babraham Institute) and St. Jude Children’s Research 8 July at the University of Strathclyde gave an insightful keynote lecture. Hospital for generous funding of in Glasgow and provided a venue for His talk covered not only the YLS2007. Most importantly we young scientists to present and scientific research of membrane would like to thank the Biochemical interact with other researchers at the lipids and associated kinases but also Society, Physiological Society and same stage in their scientific careers. discussed his road to scientific British Pharmacological Society for YLS2007 was a satellite to the main research. Our other keynote speaker, making YLS2007 such a success. Life Sciences2007 meeting. It Nina Balthasar (RCUK Fellow, Thanks! brought together young scientists University of Bristol), gave an equally from the Biochemical Society, inspiring talk relating her transition The YLS2007 Organising Physiological Society and British from a young scientist to Committee Pharmacological Society to present, independent researcher to the way in Susan Chalmers and Marnie Olson discuss and network in a setting which she has built on her research (University of Strathclyde), Patrick meant to encourage the programme and understanding of Howorth (University of Bristol), participation of MSc and PhD the field of neuronal pathways in Ahmed Khweir (University of students and post-doctoral metabolic balance. Glasgow)

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Setting the pace Otto Hutter, pictured right with Hilary Brown, gave the introductory talk at the recent Manchester meeting

Let me start by presenting my credentials as a cardiac physiologist. Early in 1946 at University College London, Sir Charles Lovatt Evans and his technician Charlie Evans set up a heart lung preparation, just so as to get things going again after the war. infancy, this was quite an insightful observation to the apex of the I was then the first, and for a while interpretation. tortoise heart, which is also devoid of nerve cells. And in an oft-quoted the only, post-war physiology Lovatt Evans told us that, by the time student, and with 3 years of war­ sentence of Talmudic complexity Stannius had focused on the sinus Gaskell argued: time employment at the Wellcome venosus as the seat of cardiac Physiological Research Laboratories rhythmicity, histologists had already behind me, I was recruited as a third ' The automatic rhythm of the shown that it contains many ventricle is of the same kind as that pair of hands. My task was to ganglion cells and nerve fibres. Here defibrinate blood collected from a of the auricle and therefore as that of is how one great Victorian the sinus, so if the latter is due to the donor dog by whisking it with a interpreted that fact: bundle of stiff wires. presence of motor ganglia so is the former; on the other hand, if the ' We know, from evidence presented former be due to some inherent Later I sat in at Lovatt Evans' lectures. by other stripped muscle and nerve, rhythmical property of the He told us how Stannius (1852) tied that the contraction of the former is ventricular muscle then the latter is ligatures between the chambers of a the result of the excitement of the due to a somewhat better frog heart and so identified the sinus latter. In like manner we know that development of the same kind of venosus as the pacemaker, and how the ganglia are centres whence that property in the muscular tissue of MacWilliam (1885) divided the heart excitement originates. We are the sinus.' of an eel and observed: therefore justified, analogically, in seeking for the sources of ' The first separated portion of By itself that argument did not at contraction of cardiac muscle in the cardiac tissue to exhibit a rhythm is once win the day. But once it was cardiac ganglia; and the experiments the ostial part of the sinus venosus. followed by Ransom’s (1885) which have been detailed – by Next the auricular basal wall shows a findings, on the octopus heart, showing that the rhythmical rhythmic action of a slower rate. And which is also composed of striated contractions continue in any part of lastly, after a long standstill the muscle, only there the ganglia are the heart which remains connected ventricle may come to exhibit a very situated outwith the heart so that with these ganglia, while it ceases in slow rhythm.' they can be extirpated, and that any part cut off from them – prove without abolishing autorhythmicity; MacWilliam understood that in the that they really are the seats of the when there followed the finding that intact heart the sinus venosus keeps regulative power'. These were the in the chick embryo the primodial the auricular rhythm in abeyance, words of the great Thomas Huxley heart beats before nerve cells reach and he interpreted the potential (1854), and with such powerful it; and finally when the situation in rhythmicity of the auricle in advocacy it took nearly half a century the mammalian heart was resolved metabolic terms, as follows: for the neurogenic doctrine to be without recourse to a nervous overthrown. ' The phase of exhaustion after a beat connection between its chambers, is gradually recovered from; the An early sceptic of the neurogenic then at last did the myogenic theory amount of energy for another theory was Michael Foster (1859; gain universal acceptance. discharge accumulates; if no 1878). He observed how cilia beat stimulus arrives from the sinus rhythmically, and he therefore held Why did the myogenic theory have venosus when the auricular tissue that rhythmicity is not confined to such an uphill struggle? I think it was has recovered sufficiently, it is readily neurones. Moreover, he found that partly because it was so much conceivable that a continued rise in small, ganglion-free pieces of snail’s against the spirit of the age. During excitability may result in a welling heart, and the similarly ganglion-free the second half of the 19th century, over in the form of a spontaneous apex of a frog ventricle, can be made Social Darwinists, like Herbert discharge of energy'. At a time when to beat spontaneously. Later Gaskell Spencer, were fond of drawing electrophysiology was still in its (1883, 1900) extended that parallels between the organization of

Physiology News | No. 69 | Winter 2007 | www.physoc.org MANCHESTER MEETING PN 9 the body biologic and that of the electrotonic coupling to non­ arouse their interest, fire their body politic. pacemaker cells: in academe, you enthusiasm for experimental may like to think, it is the physiology, so you will then be able For instance, the muscular tissues of bureaucratic load. to build on this, even to the point of the body were likened to the manual telling your student about that funny labouring class of society; the The solution seems to be for the current which has become so secretory glands to manufacturers, leading pacemakers to keep important, about the new drugs the white blood corpuscles to themselves somewhat apart, and to based on it, about novel policemen, and so on. Finally, a be sheltered by other potential bioengineered pacemakers, and nervous system dominating overall, pacemaker cells in the atrial border about all the other wonderful was likened to the commanding and zone, cells that are content most of advances it was our pleasure to learn administrative class, which on this the time just to buffer the load about at this symposium. view, justifiably crowned a represented by the auricular hierarchical society. So the myocardium. Otto F Hutter proposition that a muscular Institute of Biomedical and Life Of course, there are situations where labouring organ like the heart might Sciences, University of Glasgow, UK have a will of its own, was an idea the imposition of a sizeable load is beneficial. Take the case of that with revolutionary implications that This article is based on the potential up-start, the A-V node. was instinctively resisted. introductory talk given at The There the load represented by the Physiological Society Focused Meeting By contrast, we know now that bundle of His keeps potential pace­ on cardiac electrophysiology in everywhere generation of maker fibres – potential Manchester from 5 to 6 September. spontaneous activity depends on troublemakers when they are not what ion channels are operative in a required – more subdued than References cell; that an inward current activated would otherwise be. Angstadt JD & Calabrese JD (1989). A by hyperpolarisation contributes to hyperpolarization-activated inward current in impulse formation both in cardiac Finally, the organisation of the heart interneurons of the medicinal leech. J pacemaker cells and in nerve cells, pacemaker also teaches how vital Neurosci 9, 2846–2847. for instance the thalamo-cortical functions are best safeguarded by multiple back-up provisions – Baker K, Warren KS,Yellen G & Fishman MC neurones; moreover, the systems (1997). Defective 'pacemaker' current (Ih) in a controlling that current are similar in whether in the body or in society. In zebrafish mutant with a slow heart rate. Proc the sinus node and in neurones the slow-mo mutation in the Natl Acad Sci USA 94, 4554–4559. (Pape,1996). And just to round the zebrafish, for instance, which lacks the funny pacemaker current, a Foster M (1859). On the beat of the snail’s circle, it has now been shown that heart. Rep Br Assoc Adv Sci 29, 160. the same funny current also slower but still life sustaining heart orchestrates autorhythmicity in truly rate is maintained by the interplay of Foster M (1878). A textbook of physiology. neurogenic hearts like those of the other current systems, like the L-type Macmillan & Co, London. Ca current and the slow K current medicinal leech (Angstadt & Gaskell WH (1883) On the innervation of the Calabrese,1989). (Baker et al. 1997). One may wish heart, with special reference to the heart of that the recently failed tap water the tortoise. J Physiol 4, 43–127. So today we can see that the old supply to Gloucester and Tewksbury had been similarly safeguarded! Gaskell WH (1900). The contraction of cardiac distinction between subservient, muscle. In Textbook of physiology, ed. Schaefer labouring cardiac muscle cells and EA. Young J Pentland, Edinburgh. self-motivating, governing nerve But enough of such diversions! So I’ll cells was an illusion. Biology can no finish with a plea. When you come to Huxley TH (1854). On the present state of lecture on cardiac rhythmicity to knowledge as to the structure and function of longer be traduced to defend class nerve. Proc Roy Inst 2, 432–437. distinction. young students, don’t start by showing them pacemaker cell action MacWilliam JA (1885).On the structure and But there remain some lessons for potentials with auricular and rhythm of the heart of fishes, with special the body politic that can still be ventricular action potentials for reference to the heart of the eel. J Physiol 6, 246–286. drawn validly; for instance, from the comparison. These mean a lot to us, organisation of the sinus node, to but to students they are just traces Pape HC (1996). Queer current and which Mark Boyett and his to be memorized. Instead, please pacemaker: the hyperpolarization-activated colleagues have contributed so start by presenting them with the cation current in neurones. Ann Rev Physiol 58 299–327. much. simple classical experiments, experiments done with a piece of Ransom WB (1885). On the cardiac rhythm in The problem is how to protect the thread, a pair of scissors and perhaps invertrebrata. J Physiol 5, 261–372. leading pacemaker cells, the precious with a thermode to produce centre of originality, from being localised changes in temperature. Stannius HF (1852). Zwei Reihen physiologischer Versuche : 1 Versuche am weighed down by too great a load. Such experiments they will Froschherzen. Arch f Anat u Wiss Med 19, In the heart that load is the comprehend joyfully, they will 85–100.

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What can clinical medicine give back to physiology? John Dickinson continues his personal account with a look at an incredibly well-known phenomenon whose pathophysiology remains a ‘most intriguing mystery ’ All observations have shown that the bradycardia remains one of the most Schafer, Professor of Medicine at St common faint begins with sudden intriguing mysteries in cardiovascular Thomas' Hospital Medical School. He peripheral vasodilatation, usually physiology' (Hainsworth, 1996a). had noticed that congestive heart accompanied by bradycardia. The One popular and current view of its failure gives 'immunity from vaso­ head must be at a higher level than aetiology – which appears in several vagal syncope'. This crucial the heart. The faint reaction cannot textbooks – is that fainting is caused observation has never been refuted, be triggered in anyone lying down by 'increased activity of ... receptors though it has been largely forgotten. flat. Progressive loss of blood in a located in the left ventricle ... excited Several of my own patients with supine subject leads to a progressive by improper squeezing of the congestive heart failure have spent fall in blood pressure and eventually myocardium when the ventricles long periods propped up, or tilted to a progressive loss of contract vigorously around an head-up in bed, sometimes even consciousness. Nothing happens almost empty chamber' (Oberg & sleeping in this position, without suddenly. But typical acute fainting Thoren, 1972). Roger Hainsworth adverse effects or fainting. Sharpey can easily be brought about in has criticised this explanation also made interesting observations normal people tilted head up by because 'few receptors have been on blockages in the large veins in many manoeuvres such as blood shown to be excited in this way ... some of his patients: 'You can bleed loss, blood pooling with leg cuffs, and people with transplanted, and a subject with a block in the superior hypotensive drugs, lower body therefore denervated ventricles, vena cava in such a way that the negative pressure and emotional show similar responses to pressure above [the block] remains trauma. It can be aggravated by hypovolaemia' (Hainsworth, 1996b). exactly the same. The pressure heat, fever, coughing, micturition or This is where clinicians can throw below [the block] of course is falling, hypoxaemia. light on human physiology. I can but there is a high venous pressure in confirm an important observation the head and arm. The same thing The cardiovascular events are made by the late Peter Sharpey- can be done with an inferior vena summarised in Fig.1. During the period up to the faint itself (A to B) blood pressure is maintained by progressively increasing sympathetically-induced peripheral vasoconstriction and tachycardia. But within a few seconds blood pressure falls precipitously (C). Everything reverses. Sympathetic vasoconstrictor tone decreases and there is also active neurogenic vasodilation as the faint begins. When sympathetic nervous vasoconstrictor activity has been recorded by microelectrodes impaled in an autonomic nerve trunk, the faint is seen to begin by the abrupt cessation of sympathetic vasoconstrictor nerve activity. The heart slows because of increased efferent vagal activity. Bradycardia can be prevented by blocking efferent vagal activity with atropine, but fainting still occurs because of widespread active vasodilation (Barcroft & Edholm, 1945). All changes quickly reverse if the subject lies flat, or is retransfused. Figure 1. Graphic diagram of the sequence of events (time running from left to right) in the minutes before, during and after a faint, induced in a normal supine adult ' What suddenly switches off this volunteer by head-up tilting in a warm room. The appropriate compensatory compensation (at the onset of a mechanisms were maintaining blood pressure and adequate brain blood supply until faint) to result in vasodilation and the blood pressure fell suddenly and the subject lost consciousness (see text).

Physiology News | No. 69 | Winter 2007 | www.physoc.org LIVING HISTORY PN 11 caval block, maintaining a high pressure in the lower half of the body with a falling pressure in the heart and they [the patients] will faint. We suggest, therefore, that somewhere between the top of the superior vena Figure 2. Two typical single fibre records from afferent nerves arising from the right cava and the bottom of the superior atrium of a cat, and joining the right vagus nerve. Venous pressure was low in this vena cava there is a reflex case, and the atrial fibre discharges only two impulses between each P and QRS wave. mechanism, if there is a reflex at all' The later burse of 5 impulses comes from an arterial baroreceptor (from Dickinson, (Sharpey-Schafer). These marvellous 1950). – but never definitively published – than under-filled. Landgren had clinicians can suggest a solution to observations pin down a site either in observed that carotid sinus an interesting and well-studied the right atrium or in the large baroreceptor discharge rate could physiological phenomenon. systemic veins close to the heart, actually increase when the artery This article and my previous one where a normal or increased venous collapsed. 'Increased impulse (Physiology News 66, 10–12) have pressure prevents fainting. But what discharge is due to deformation of given examples of ways in which is the receptor? How does it work? the arterial wall at low pressures' clinical medicine can contribute to (Landgren, 1952). This phenomenon physiology. My final piece, to be Sixty years ago David Whitteridge was later described as 'collapse­ published in a future issue of had set me the task of comparing firing' of baroreceptors. Physiology News, will look at cardiac fluctuations of the right atrial Hippocratic fingers. I have described pressure of cats with simultaneously Mechanical activation of atrial many more medical mysteries from a recorded patterns of afferent nerve receptors (or electrical stimulation of physiological viewpoint in my discharge from low-pressure venous the cut central ends of the cardiac recently published book (Dickinson, baroreceptors in the right atrium. I vagal filaments) produces reflex 2005). used anaesthetised artificially­ systemic vasodilatation and ventilated open-chest cats in a steam invariably slows the heart. Afferent John Dickinson chamber, recording afferent vagal baroreceptor impulses Wolfson Institute of Preventive baroreceptor impulses in nerves terminate in the solitary tract Medicine, London, UK coming from the right atrium to join nucleus in the medulla, at which site the right vagus nerve (Fig. 2). The opiate receptors are present in high References main burst of impulses began density. The opiate antagonist immediately after the P-wave of the Barcroft H & Edholm OG (1945). On the naloxone inhibits the early vasodilatation in human skeletal muscle ECG, at the time that atrial pressure cardiovascular effects of blood loss in during posthaemorrhagic fainting. J Physiol was at its highest (Dickinson, 1950). I man. This region of the brain stem 104, 161–175. could identify the site of origin of the receives projections from the Dickinson CJ (1950). Afferent nerves from the receptors by lightly touching the amygdala and hypothalamus and heart region. J Physiol 111, 399–407. right atrial wall with a glass rod. This might be the common path for the produced a shower of nerve impulses Dickinson CJ (1993). Fainting precipitated by initiation of emotional fainting. collapse-firing of venous baroreceptors. Lancet when the receptors at the site were 342, 970–972. those whose impulses I was Collapse-firing of low pressure recording. I could obtain an baro(stretch)-receptors in the right Dickinson CJ (2005). Medical mysteries. Book Guild, Lewes. impressive torrent of impulses from atrium and great veins, possibly on many adjacent atrial receptor sites by the left side as well, plausibly and Hainsworth R (1996a). Physiology and gently pushing in the right atrial wall completely explains the sequence of pathophysiology of syncope. In Syncope in the older patient, ed. Kenny RA, pp 15–32. with my fingertip. events in the common faint. I Chapman & Hall, London. published this hypothesis in 1993 I remembered this experience when I (Dickinson). It has so far been neither Hainsworth R (1996b). The physiological approach to cardiovascular reflexes. Clin Sci began to think about the cause of criticised nor disproved. I hope that 91(Suppl), 43–49. fainting. By this time I was clinically one day it will be tested by experienced. I had read Sharpey' s investigators who can watch human Landgren S (1952). On the excitation mechanism of the carotid baroreceptors. Acta clinical observations and logical right atrial wall movements by physiol scand 26, 1–34. conclusions about fainting. It ultrasound imaging as a faint begins. suddenly flashed across my mind I have not yet located collaborators Oberg B & Thoren P (1972). Increased activity in left ventricular receptors during that the mysterious faint reaction with equipment, facilities and hemorrhage or occlusion of caval veins in the could be explained by the sudden volunteers – and with enough cat. A possible cause of the vasovagal collapse of unfilled low pressure curiosity – to examine this reaction. Acta physiol scand 85, 164–172. veins and right atrium. This could fascinating problem. Meantime it Sharpey-Schafer EP (1952). General signal false information to the brain remains an example of the way in discussion. In Visceral circulation (CIBA – that the heart was over- rather which observations made by Symposium), p 268. Churchill, London.

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How to get good science David Colquhoun considers how a university can achieve the best research and teaching, and the most efficient administration – the aim of every university vice-chancellor (president, rector or provost) in the country

Academics, like everyone else, are Imagine how you would feel if you Garfield still hasn't understood expected to do a good job. They are were sent every year a spreadsheet though. As the examples below show, paid largely by taxpayers, and that showed your publication score the citation rate is itself a very dubious taxpayers have every right to demand and financial viability, and showed measure of quality. Garfield quotes value for their money. The problem is these things for all your colleagues too. approvingly: that it is very hard to measure the Well, you may say, there's nothing value of their output. Most of the ideas wrong with knowing how you are ‘ Impact factor is not a perfect tool to that have made life as comfortable as it doing. But imagine too that your measure the quality of articles, but is in the affluent West have their publication score is entirely there is nothing better, and it has the origins in science departments in automated, with no attempt to advantage of already being in universities, but it isn't possible to measure the quality of what you are existence and is therefore a good place a monetary value on, say, James doing. And imagine that if your grants technique for scientific evaluation.’ Clerk Maxwell 's equations of don't cover your costs, you are in (Hoeffel, 1998) electricity and magnetism, or on danger of being fired. And imagine Bernard Katz's work on synaptic that your meetings with senior And you can't get much dumber than transmission. Still less is it possible to colleagues consist of harassment about that. It is a ‘good technique’ because measure the contributions of A E what journals you publish in, and how it is already in existence? There is Housman, Stanley Spencer or Augustus many grants you have, not a discussion something better. Read the papers. John (all UCL people, as it happens). of your scientific aims. Not so good, you may think. But this is exactly what Try asking an impact factor enthusiast This paper describes one example of has been happening at Imperial why it matters that the distribution of what happens when universities College Medical School. citation numbers for a given journal is change from being run by academics highly skewed, and you will usually be to being run by managers. It describes Let's take a closer look at how met with a blank stare. One effect of an effect of corporatisation in the academics are being assessed. the skew is that there is no detectable medical school of Imperial College correlation between impact factor and London, but the same trends are Imperial's ‘publication score’ citation rate (see, for example, Seglen, visible in universities throughout the The publication score that appears 1997; Colquhoun, 2003) . The easiest world. The documents on which it is alongside that of your colleagues is way to illustrate the numb-skulled based were sent to me after I'd written calculated thus. nature of this assessment is with a few ‘All of us who do research (rather than examples. talk about it) know the disastrous Multiply the impact factor of the effects that the Research Assessment journal by the author position weight, Publication score versus citation Exercise (RAE) has had on research in and divide by the number of authors. Take a selection of 22 my own the United Kingdom: short-termism, The author position weight is 5 for the publications (the selection is arbitrary: intellectual shallowness, guest first and last author, 3 for the second it spans a range from 15 to 630 authorships and even dishonesty ’ author, 2 for the third author and 1 for citations and omits some of the dross). (Colquhoun, 2007). any other position. Fig. 1A shows that the well-known lack of correlation between citations and The problem is not so much the RAE This index is clearly the invention of an impact factor is true for me too. Fig. 1B itself (the last one was done much uninformed incompetent. That is shows the same for the publication better than the assessment described obvious for a start because it uses the score. below), but rather it is the effect that impact factor. The impact factor is a the RAE has had on university (superfluous) way of comparing The highest publication score (77.3) managers, who try to shape the whole journals. It is the invention of Eugene was for a two page perspective in university in their misperception about Garfield, a man who has done Science , with a mere 41 citations its methods. It is another example of enormous harm to true science. But (Sivilotti & Colquhoun, 1995). As Goodhart's law. The problem arises even Garfield has said: perspectives go, it was fine. But it when people with little understanding seems that this was 7.2 times more of scholarship, or of statistics, attempt ‘ In order to shortcut the work of valuable than my best ever paper (on to measure numerically things that looking up actual (real) citation counts which I was recently asked to write a cannot be so measured. That is a for investigators the journal impact classical perspective) which has a plague of our age (Colquhoun, 2006), factor is used as a surrogate to publication score of only 10.7 (but 565 but it is a process loved by politicians, estimate the count. I have always citations) (Colquhoun & Sakmann, ‘ human resources’ people and warned against this use.’ 1985). My lowest publication score (in university managers. (Garfield, 1998) this selection) is 2.08. That is for a

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The divisional minimum benchmarks are ‘To have sufficient papers in top rated journals in the speciality to ensure four publications in the RAE review period (2001–2007) with an Impact Factor of at least 5 and with no overlap with co-authors from Imperial’

The ‘productivity’ target for publications is "To publish three papers Figure 1. A, number of citations versus impact factor (log-log scales). B, number of per annum including one in a citations versus ‘publication score’ (log-log scales). prestigious journal with an impact factor of at least 5". Unfortunately, Hawkes et al. (1992) , a mathematical In the early days of gigohm seal Harald Dr X has published only two papers in paper which provides the method Reuter decided that he wanted to learn 2006 ... needed for maximum likelihood fitting the method, and to achieve this he of single channel recordings, without invited three of us who already had Let's see who lives up to their which most of my experimental work some experience of the method to ‘productivity’criterion. could not have been done; its spend part of the summer vacation in mathematical difficulty may account Bern. We had a wonderful summer Take, for example two scientists who for its modest number of citations (42) there, and being somewhat command universal respect in my own but its value for our work has been overmanned it was not very stressful. It field – Erwin Neher and Bert Sakmann. enormous after the maths was put into would, I think, be fair to say that all They got the Nobel Prize for Physiology a computer program that can be used four of us did much the same amount or Medicine in 1991. In the 10 years by the semi-numerate. of work. While recording we noticed a from 1976 to 1985, Sakmann type of channel that was opened by published an average of 2.6 papers per Citations versus value: a real life intracellular calcium, like the calcium­ year (range 0 to 6). In 6 of these 10 story activated potassium channel that was years he failed to meet the publication The dimwitted nature of the already well known in 1981. This one target set by Imperial, and these publication score, and also of using was a bit different because it was not failures included the years in which the citation rates, can be illustrated in selective for potassium. We hadn' t original single channel paper was another way. Consider some of the expected to get a paper out of the published (Neher & Sakmann, 1976) background to a couple of examples; vacation job but it seemed novel and also the year when Colquhoun & these are the real life facts that are enough to write up, and 1982 being a Sakmann (1985) was published. ignored by bean counters. year when anything with ‘single channel’ in the title, however trivial, In 2 of these 10 years he had no Colquhoun & Sakmann (1981) got a sailed into Nature, and because we had publications whatsoever. score of 73.2 and 278 citations. It was a limited amount of data, we sent it there. Because we had all contributed a three page Nature letter, a first stab On the other hand, a paper in 1981 in a much the same amount of work, we at interpretation of the fine structure journal with an ‘unacceptable’ impact put the authors in alphabetical order. of single channel openings. It wasn' t factor of 3.56 has had over 15000 The analysis of the results, such as it bad, but since Nature papers are so citations (Hamill et al. 1981). This was, was crude in the extreme (paper short they mostly can't be thought of paper would have earned for Sakmann charts unrolled on the floor and as real papers, and 4 years later we a publication score of a miserable 0.71, published the work properly in The measured with a ruler). If we hadn' t less than 100th of our perspective in Journal of Physiology (Colquhoun & seen this particular channel subtype, Science. Sakmann, 1985), the result of 6 years someone else would have done with a work (57 pages, 565 citations). For this year or two. It just happened to be the Imperial would have awarded me a first one of its type and so has been All this shows what is obvious to publication score of a mere 10.7. cited a lot, despite being scientifically everyone but bone -headed bean trivial. counters. The only way to assess the Here is another interesting case. If we merit of a paper is to ask a selection exclude chapters in Single channel This example shows not only the of experts in the field. Nothing else recording (Neher & Sakmann, 1983; iniquitous uselessness of the works. Nothing. 1995) which apparently don't count, publication score used by Imperial; it my most highly cited paper is also shows dramatically the almost It seems to have escaped the attention Colquhoun, Neher, Reuter & Stevens equal uselessness of counting of bean counters that this is precisely (1981). This has 630 citations and a citations. what has always been done by good publication score of 36.6 for me, grant giving agencies and search and though only 14.6 for Harald Reuter. How not to get Nobel prizes promotion committees. Academics The reality behind this paper is as Employees of Imperial Medical School have always been assessed. But before follows. are told: HR departments and corporate-

Physiology News | No. 69 | Winter 2007 | www.physoc.org 14 PN SOAPBOX academics got involved, it was done References competently. Now a whole branch of Colquhoun D (2003). Challenging the tyranny pseudo-science has appeared which of impact factors. Nature 423 , 479. devotes itself to trying to find ways of assessing people without bothering to Colquhoun D (2006). Playing the numbers find out what they have done. game. A book review, of Does measurement measure up? How numbers reveal and conceal ‘Bibliometrics’ is as much witchcraft the truth by John M. Henshaw. Nature 442 , as homeopathy. How long, one 357. wonders, will it be before somebody coins the term ‘bibliomics’? (Oops, a Colquhoun D (2007). Science degrees without Google search shows I'm too late, some the science. Nature 446 , 373–374. numbskull has already done it). Colquhoun D (2007). What have we learned from single ion channels? J Physiol 581, How to get good science 425–227. Universities will have to decide what sort of science they want. Colquhoun D, Neher E, Reuter H, & Stevens CF (1981). Inward current channels activated by They can bend their policies to every intracellular calcium in cultured cardiac cells. whim of the RAE; they can bow to the Nature 294 , 752–754. pressures for corporatisation from the Sakmann in Göttingen, 1980. He and funding council. Neher did the work themselves. Colquhoun D & Sakmann B (1981). Fluctuations in the microsecond time range of the current through single acetylcholine Or they can have creative scientists receptor ion channels. Nature 294 , 464–466. who win the real honours. further fall in the public's trust in science. That trust is already Colquhoun D & Sakmann B (1985). Fast events They cannot have both. disastrously low, and one reason for in single-channel currents activated by that is, I suggest, pressures like those acetylcholine and its analogues at the frog muscle end-plate. J Physiol 369 , 501–557. If they want to have the latter they will described here which lead scientists to publish when they have nothing to say. have to have universities run by Garfield E (1998). http://www.garfield.library. academics. And they will have to avoid upenn.edu/papers/derunfallchirurg_v101(6)p corporate and commercial pressures. I wrote recently (Colquhoun, 2007) ‘All 413y1998english.html. They will have to resist the pressures to of us who do research (rather than talk remove power from their best about it) know the disastrous effects Hamill OP, Marty A, Neher E, Sakmann B, & that the Research Assessment Exercise Sigworth FJ (1981). Improved patch clamp researchers by abolishing eminent techniques for high resolution current departments and centralising power at has had on research in the United recording from cells and cell-free membrane a higher level. We have seen what this Kingdom: short-termism, intellectual patches. Pflügers Arch 391, 85–100. approach has done to the NHS, but it is shallowness, guest authorships and a characteristic of the corporatising even dishonesty’. Now we can add to Hawkes AG, Jalali A, & Colquhoun D (1992). that list bullying, harassment and an Asymptotic distributions of apparent open mentality to ignore or misuse data. times and shut times in a single channel They just know they are right. incompetent box-ticking style of record allowing for the omission of brief assessment that tends to be loved by events. Philosophical Transactions of the Royal It is also the box-ticking culture of HR departments. Society London B 337, 383–404. managerialism that has resulted in approval of BSc degrees in anti-science This process might indeed increase Hoeffel, C. (1998) Journal impact factors Allergy 53, 1225. (Colquhoun, 2007). Impressive your RAE score in the short term sounding validation committees tick (though there is no evidence that it Neher E & Sakmann B (1976). Single channel all the boxes, but fail to ask the one does even that). But, over a couple of currents recorded from membrane of question that really matters: is what is decades, it will rid universities of denervated frog muscle fibres. Nature 260, being taught nonsense? potential Nobel prize winners. 799–802.

New York Times. See The policies described here will result David Colquhoun http://www.dcscience.net/improbable.html#clone in a generation of 'spiv' scientists, Department of Pharmacology, churning out 20 or even more papers a University College London, UK Seglen PO (1997). Why the impact factor of year, with very little originality. They journals should not be used for evaluating will also, inevitably, lead to an increase research. Br Med J 314, 498–502. in the sort of scientific malpractice that This article is an extended version of Sivilotti LG & Colquhoun D (1995). was recently pilloried viciously, but comments published in the Times Higher Acetylcholine receptors: too many channels, accurately, in the New York Times, and a Education Supplement on 1 June 2007. too few functions. Science 269, 1681–1682.

Comments on this article can be left at DC’s Goodscience blog ( http://www.dcscience.net/goodscience/?p=4) or at DC’s Improbable Science blog (http://www.dcscience.net)

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From lamprey swimming to human stepping: evolutionary conservation of longitudinally-propagated spinal activity

A diverse array of biomechanical We have recently begun to address a systems has evolved to satisfy number of unresolved questions locomotory requirements (flight, concerning the functional reptation, swimming, walking, etc.) organization of spinal networks within the animal kingdom' s involved in trunk muscle activation different environments. Effectively, during limb-based locomotion. What the ability to move from one place to are the neural circuit substrates for another requires reconciliation Jean-René Cazalets (left) and Mélanie coordinated hind-limb and trunk between conflicting behavioural Falgairolle. movements during actual objectives, in that the seemingly locomotion in quadruped mammals, straightforward demand of an generators (CPGs), that for the fore­ and to what extent have these animal to actively move towards a and hind-limbs of quadruped neuronal networks been preserved target necessitates the disruption of animals are located within the during the course of evolution? the fragile postural equilibrium that lumbar and cervical spinal cord has to be dynamically adjusted as regions, respectively. In limbless To explore the simultaneous body displacement proceeds. Thus anguilliform animals such as functioning of the trunk and hind­ the successful achievement of tadpoles, lamprey and snakes, body limbs during actual locomotion, we locomotor movement requires the propulsion is driven by alternate left­ have used both in vivo behavioural integrated functioning of all body right trunk muscle contractions that observations and in vitro segments, including the fore- and occur sequentially in an anterior-to­ electrophysiological approaches with hind-limbs, trunk, head, and the posterior direction along the body the neonatal rat as our experimental synergistic action of many other length. The CPGs that control such model. In a first instance, to study muscle groups to ensure the rhythmic trunk bending have been coordinated back and tail appropriate positioning of the shown to be segmentally-distributed movements during behaviour, rat different body regions. along the whole spinal cord axis. In pups were tagged with a series of ink limbed vertebrates, however, very dots placed along the dorsal axial From numerous studies on a variety few studies have explored the role of line and were filmed during actual of vertebrate organisms, it is now trunk muscle contractions during locomotion (Fig. 1A, 1B). By then well established that the basic motor locomotion, although a cyclic determining the spatial coordinates patterns underlying limb and trunk contraction of trunk muscles in time of individual dots, regionally-specific movements during locomotion are with rhythmic limb movements has body positions and angles could be driven by central networks of been reported in various species (cat, computed. Since, the rat pup does neurons, so-called central pattern rat and man). not yet exhibit spontaneous locomotion at this age, forward progression was elicited by holding a tube containing nest material in front of the animal's nose. As the animal moves towards the scent, the experimenter slowly withdraws the tube so that the animal follows it. Our 2D kinematic analysis showed that there is a rhythmic sequential change in trunk curvature during each step cycle of locomotor activity (Fig. 1C). Moreover, this rhythmic trunk bending is propagated from tail-to-head and the bending amplitude is larger in the lower back than in the upper thoracic body region.

Figure 1. Two-dimensional kinematic analysis of trunk movements in newborn rat. We next sought to identify the origin (A) trajectories of dots during 4 s of walking. (B) Drawing indicating the position of and central distribution of spinal analysed points and angles. (C) Mean angular change reflecting complete trunk motoneurons supplying axial (trunk) bending during a step. (D) Plot of the maximum angle amplitude occurring during musculature in the newborn rat. This one cycle. Each colour corresponds to the angle in B.

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not be explained solely on the basis of axonal conduction velocities and synaptic transmission delays. Rather, it is likely that both long multi­ segmental neuronal pathways as well as local circuit interactions between adjacent segmental oscillators are involved in the coupling.

The data reported in our paper has allowed a functional diagram of interacting spinal networks to be proposed. In this model, the bursting properties of each spinal segment facilitate the transmission of motor activity along the spinal cord, while local intersegmental synaptic Figure 2. Simultaneous recordings of 16 ventral roots during locomotor-like activity interactions also contribute to showing a propagation wave from tail to head. A1, Drawing of the preparation with activity propagation. Cross-cord dots indicating electrode location. A2, Recordings of locomotor-like activity induced connections ensure bilateral by bath-application of serotonin and excitatory amino acids. A3, Schematic coupling along the cord length, and representation of propagating process occurring in 4 sacral ventral roots. The arrow indicates the direction of the propagation. Horizontal black boxes in each trace long propriospinal pathways are also indicate bursting duration during successive locomotor cycles. involved in coordination. The rostral part of the lumbar cord enlargement was achieved by the intra-muscular assess the global functioning of provides rhythmic locomotor-related injection of a retrograde marker spinal circuitry and to understand output to rhythmic network (cholera toxin B subunit) which is how the thoracic, lumbar and sacral elements in neighbouring segments taken up by motor axon terminals in segments interact, we recorded from that in turn convey and modulate the muscle and migrates into up to 16 ventral motor roots output to their corresponding motoneuron cell bodies within the simultaneously along the thoraco­ segmental motoneurons. In the spinal cord over the ensuing 24 h. lumbo-sacral spinal cord axis (Fig. intact spinal cord, the lumbar cord This revealed that motoneurons 2A1, 2A2). A major finding from this region probably imposes its own innervating the axial muscles are approach is that waves of rhythmic timing on the thoracic spinal cord distributed along the entire spinal activity are propagated sequentially generators, as it also does for the cord, from thoracic to coccygeal to the various ventral roots along the more rostral sacral segmental segments and including the lumbar cord from sacral (posterior) to upper generators. segments where they co-localize (anterior) thoracic segments (Fig. with motoneurons that innervate the 2A3). This intra-spinal discharge in The first important conclusion of this hind-limbs. which one cord region is activated study is that the rhythmic motor after another, has been termed pattern that drives back muscle Finally, using isolated spinal cord 'metachronal' motor activity. activation is centrally generated. preparations, we have analysed the In vitro experiments where the Secondly, the metachronal nature of functional interactions between the isolated cord was sectioned at the propagating motor pattern is various cord regions during centrally­ different levels have revealed three also centrally determined and generated motor activity in vitro. zones (thoracic, lumbar, sacral) in remains strictly coordinated with Sequences of 'fictive' locomotion, which the spinal motor networks hindlimb motor activity. Moreover, i.e. rhythmic locomotor-related possess the intrinsic capacity for our data suggest that the networks activity produced in the absence of generating rhythmic motor output. responsible for the metachronal actual movement (since the spinal This approach also provided propagation of motor patterns cord is physically isolated from important insights into the during mammalian locomotion may muscles and sensory inputs), were underlying synaptic organization. correspond to those observed in elicited by the bath-application of a First, rhythmic burst generation lower vertebrates and even mixture of the monoamine, continued to occur in the invertebrates, and thus appear to serotonin, and excitatory amino­ longitudinally-sectioned hemi-spinal have been highly conserved during acids (Cazalets et al. 1992). The core cord, indicating that the central evolution. Interestingly, metachronal networks that generate hindlimb circuitry does not require cross-cord propagation is not only restricted to locomotor activity in rat were connections to generate locomotor­ undulating or quadrupedal previously found to be located in like output. Second, based on the organisms. By investigating back lumbar segments L1 and L2 of the relative timing of motor bursts, it muscle activity in humans we have spinal cord (Cazalets et al. 1996). To appears that the travelling wave can recently found a comparable

Physiology News | No. 69 | Winter 2007 | www.physoc.org FEATURES/SENSE ABOUT SCIENCE PN 17 sequential activation during various There goes the science Other companies were called to back modes of forward bipedal up decisions they had made on locomotion (manuscript in bit … behalf of their customers. The Co-op preparation). Presumably, such a A group of young scientists and Sainsbury’ s have both recently ubiquitous organization serves to hunt for the evidence behind banned certain substances from assist in dynamic postural their food and drink products (MSG adjustments to ensure fluent body advertising claims and sodium benzoate respectively), and limb movements during Detox patches that ‘draw out toxins implying that these may cause harm, locomotion. from your body overnight’ and despite a lack of any evidence to pendants that ‘balance your biofield’ suggest this. When pressed, both Mélanie Falgairolle – almost all of us can give our own companies admitted that the Jean-René Cazalets examples of science frustratingly or substances were removed due to amusingly misrepresented in Universités Bordeaux 2 and 1, CNRS, ‘ customer concerns’ and not any advertising. Discussing my own evidence of health risks. Bordeaux, France pseudoscience pet hates with a group of PhD and post-doctoral Does it matter when companies References scientists, I realised I was far from misrepresent science? It is not just Cazalets JR, Borde M & Clarac F (1996). The that such misleading or exaggerating synaptic drive from the spinal locomotor alone in being fed up with junk network to motoneurons in the newborn rat. J science, and was thrilled when my can waste people’s money, or even Neurosci 16, 298–306. colleagues rang companies and affect their health. People trust these challenged them to back up their companies. When Sainbury’ s or Pret Cazalets JR, Sqalli-Houssaini Y & Clarac F a Manger decide to exclude ‘obscure (1992). Activation of the central pattern claims. As they shared the resulting generators for locomotion by serotonin and conversations on the Voice of Young chemicals’ because of public excitatory amino acids in neonatal rat. J Physiol Science (VoYS) forum, the idea perceptions, they cause distrust in 455, 187–204. began to catch on, and transcripts of what scientists say, because Pret says otherwise. Customers expect Falgairolle M & Cazalets JR (2007). conversations with manufacturers Metachronal coupling between spinal and retailers ranging from obscure advertisers to base claims on neuronal networks during locomotor activity internet brands to big high street evidence, especially when scientific in newborn rat. J Physiol 580, 87–102. names began to roll in. language is used (or misused) to make them sound more credible. In brief Amazingly, none of the companies When companies behave as if called managed to provide any evidence does not matter, they are Book discount scientific evidence to back up their not only deceiving their customers, The Physiological Society has claims. Many made impressive they are devaluing science for teamed up with Wiley-Blackwell statements about their products’ everyone. to offer Members, Affiliates and abilities, but were unable to even Associates of The Society a 25% explain how they worked. ‘Detox Like the Voice of Young Science discount on book purchases. For patches’ sold by the beauty spa group, we need to let companies more information visit the Champneys, are designed to be stuck know that they are accountable for Members’ area of the web site. to your feet, and overnight turn from their misuse of science. If we Access for Affiliates and white to dark brown, supposedly scrutinise these claims, advertisers Associates will be available shortly indicating that ‘toxins have been are forced to ensure that they have via the new web site. In the drawn out of your body.’ As the the evidence to back them up. As meantime please contact Sarah ‘ harmful toxins’ named included VoYS has shown, it only takes a Ollington for further details such essential substances as fatty phone call to challenge your own ([email protected]) acids, biologist Aarathi Prasad felt pseudoscience pet hate. If not you, then who? Life science blogs the claims required further The number of life science blogs is investigation. VoYS has produced There goes the steadily increasing and there is science bit… - a dossier of their little guidance for newcomers on Several phone calls to Champneys amusing, eye-opening and the must-read blogs in their area. and the patch manufacturer, Trading sometimes shocking experiences, The Scientist is therefore Angels, informed Aarathi that the hoping to inspire others to stand up compiling a list of the best life patches had ‘been tested’ (though for science too. For a free copy, or science blogs. For more they didn’t know how, or with what more information, go to information and to vote on your results), and no-one could explain www.senseaboutscience.org or favourite blog visit exactly how they worked. The fact contact Alice Tuff at http://www.the-scientist.com that the patches contain wood [email protected] vinegar, which turns brown on For news updates visit contact with moisture (for example, Kate Oliver http://www.physoc.org/news on sweaty feet), went unanswered. Member, Voice of Young Science

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Brain rhythms, synaptic plasticity and sleep

EEG recordings from the scalp latter possibility would be in line disclose rhythmic electrical activity with the alternating occurrence of resulting from repetitive discharges non-REM and REM episodes during of thousands of interconnected sleep and the fact that most neurons in the forebrain. The experimental memory tasks frequency and synchrony of these inherently consist of a combination rhythms change with the state of of different types. vigilance. During wakefulness and rapid-eye movement (REM) sleep It is widely accepted that changes in synaptic connectivity underlie fast oscillations (10–40 Hz) of low Daniel Ulrich amplitude are prevalent, while memory formation and learning during non-REM sleep slower While fast oscillations during (Rioult-Pedotti et al. 2000). In rhythms (0.1–4 Hz) are highly wakefulness have been implicated in particular, long-term potentiation synchronized over large areas of the sensory processing and memory (LTP) and depression (LTD) are long­ forebrain. Associated with these formation (Gray & Singer, 1989) the lasting increases or reductions in state-dependent changes in global slow rhythms seem to play a role in synaptic strength that are considered brain activity are character-istic reorganizing neural networks during to be important cellular mechanisms alterations in the firing patterns of sleep. There is accumulating underlying learning and memory thalamic and cortical neurons evidence, mainly from behavioral formation. How, then, is synaptic (Steriade et al. 2001). During fast EEG studies, that both REM and non-REM strength influenced by the various rhythms, i.e. wakefulness and REM sleep have an important influence on discharge patterns observed during sleep, action potentials are memory formation and learning sleep? generated as continuous trains of (Walker & Stickgold, 2004). Recent experiments in layer V individual spikes (tonic mode), while According to the ‘parallel ’ pyramidal cells of rat somatosensory during non-REM sleep they are hypothesis, non-REM and REM sleep cortex in vitro have used a emitted as high frequency bursts affect different types of memories, stimulation paradigm where (burst mode) where action i.e. declarative and procedural, excitatory synaptic potentials potentials are grouped together by a respectively. In the ‘sequential’ (EPSPs) were elicited in close transient depolarizing potential model all forms of memory are temporal proximity with single (Fig. 1A). affected by both sleep episodes. The action potentials or burst-discharges A B to mimic the near-synchronous activity of synaptically coupled neurons during wakefulness or sleep, respectively (Fig. 1B) (Birtoli & Ulrich, 2004). The results show that associations of EPSPs with single spikes predominately lead to LTP while associations of EPSPs with bursts induce an enduring reduction C D of the excitatory synaptic inputs (burst-LTD) (Fig. 1C, D). This suggests that firing patterns characteristic of wakefulness and sleep differentially affect synaptic plasticity. Pharmacological experiments revealed that while LTP was reliant on the NMDA (N-methyl­ D-aspartate) subtype of glutamate receptors, burst-LTD depended on the concomitant activation of Figure 1. A, Action potentials can be generated as individual spikes (left) or high metabotropic group I glutamate frequency bursts (right). B, The influence of single spike and burst firing on synaptic receptors and low-threshold plasticity was assessed by pairing excitatory synaptic potentials (EPSPs) with single activated Ca2+ channels (Czarnecki et spikes or bursts. Composite EPSPs are elicited by extracellular stimulation and al. 2007) (Fig. 2A). The concurrent ‘ paired’ repetitively with a postsynaptic action potential or spike burst (figurine). activation of both signalling C, D, EPSP-amplitude time series illustrating the impact of single spike-pairings 2+ (green) and burst-pairings (red) on synaptic strength. The pairing periods are pathways leads to a release of Ca indicated by horizontal bars and outlined schematically in the figurine. from internal stores and activation of

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A While we have shown that character­ istic sleep/wake discharge patterns differentially influence synaptic strength, other factors like state­ dependent changes in neuromo­ dulator concentrations are likely to affect synaptic plasticity as well.

Overall, there is growing evidence from different fields in neuroscience for a role of sleep in reorganizing neural circuits associated with memory formation. This would add B C another dimension to the function of sleep that is more traditionally believed to merely subserve energy replenishment.

Daniel Ulrich Department of Physiology, Institute of Neuroscience, Trinity College, Dublin 2, Ireland

References Birtoli B & Ulrich D (2004). Firing mode­ dependent synaptic plasticity in rat Figure 2. A, Schematic outline of the signaling pathway involved in burst-LTD. neocortical pyramidal neurons. J Neurosci 24, Coactivation of metabotropic glutamate receptors and T-type Ca2+ channels leads to 4935–4940. Ca2+ release from internal stores and activation of proteinkinase C. Phosphorylation of AMPA receptors by this enzyme leads to their removal via endocytosis. B, Relationship Czarnecki A, Birtoli B, & Ulrich D (2007). between the initial size of the EPSP and the amount of LTP and burst-LTD. Cellular mechanisms of burst firing-mediated long-term depression in rat neocortical C, Hypothetical evolution of synaptic weights undergoing LTP (red) or no change pyramidal cells. J Physiol 578, 471–479. (black) without (above) or with (below) synaptic rescaling. Note the relative synaptic weight compression in the lower graph. Fischer S, Nitschke MF, Melchert UH, Erdmann C & Born J (2005). Motor memory protein kinase C (PKC). This enzyme decrease of cortical spike activity consolidation in sleep shapes more effective promotes the endocytosis of AMPA (Fischer et al. 2005). This may neuronal representations. J Neurosci 25, receptors, which is the ultimate indicate that memory improvement 11248–11255. cause of a long-lasting depression of may be associated with a relative Gray CM & Singer W (1989). Stimulus-specific excitatory synaptic inputs (Fig. 2A). strengthening of particular neuronal oscillations in orientation columns of The concomitant requirement for connections by reducing the overall cat visual cortex. Proc Natl Acad Sci USA 86, presynaptic (i.e., neurotransmitter effectiveness of synaptic inputs. 1698–1702. release) and postsynaptic (action Indeed, preliminary data in vitro Moser EI, Krobert KA, Moser MB & Morris RG potential bursts) activity explains the suggest that burst-LTD affects homo­ (1998). Impaired spatial learning after associative nature of burst-LTD and hetero-synaptic inputs as saturation of long-term potentiation. Science (Birtoli & Ulrich, 2004). expected for such a rescaling 281, 2038–2042. mechanism. Another potential Further experiments revealed that Rioult-Pedotti MS, Friedman D & Donoghue JP important role of synaptic (2000). Learning-induced LTP in neocortex. the amount of LTP is proportional to downscaling is to keep synaptic Science 290, 533–536. the initial EPSP size, while burst-LTD strengths within a physiological was inversely related to the baseline dynamic range. This would prevent Steriade M, Timofeev I & Grenier F (2001). amplitude of the EPSP (Fig. 2B). synapses from being driven into Natural waking and sleep states: a view from Downscaling of synaptic weights has inside neocortical neurons. J Neurophysiol 85, saturation and thus allow their reuse 1969–1985. been postulated as a major over consecutive waking periods mechanism by which non-REM sleep (Fig. 2C). It has been shown Tononi G & Cirelli, C (2003). Sleep and contributes to memory consolidation previously that LTP can be saturated synaptic homeostasis: a hypothesis. Brain Res (Tononi & Cirelli, 2003). Indeed, it and that this impedes further Bull 62, 143–150. was recently found that sleep-related learning (Moser et al. 1998). Thus a Walker MP & Stickgold, R (2004). Sleep­ improvement of a trained motor task synaptic rescaling process is likely to dependent learning and memory is accompanied by an overall be of physiological relevance. consolidation. Neuron 44, 121–133.

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Tropomyosin mutations responsible for muscle weakness in inherited skeletal muscle diseases Several mutations have been identified in tropomyosin, a key regulatory protein in muscle fibres. These mutations specifically modify muscle fibre function, and result in general muscle weakness accompanied with various inherited skeletal myopathies

In skeletal muscle fibres, tropomyosin, a regulatory protein, coils around the actin filament, relaying the information from the Ca2+ sensor, the troponin complex to the actin-myosin interactions, the cross-bridges. Tropomyosin alternates between three positions: the blocked, closed and open states.

In the absence of Ca2+, tropomyosin is in a position on the outer domain of actin that sterically hinders the docking of cross-bridges – the blocked state. Full activation by reversal of steric blocking involves two additional states, requiring successive tropomyosin movements away from the blocked Figure 1. Mutations affecting β and γ tropomyosin isoforms. Eight mutations in the configuration. Ca2+ bindings to the TPM2 and TPM3 genes have been associated with amino acids changes on the β troponin complex cause (Arg91Gly, Glu117Lys, Arg133Trp, Glu139del, Glu147Pro) and γ (Met9Arg, Glu31stop, tropomyosin movement toward the Arg167His) tropomyosin isoforms. inner domain of actin, exposing sites that allow weak binding of myosin mutations in the TPM1, TPM2, and inherited diseases, in the absence of heads while still inhibiting TPM3 genes have been reported to muscle wasting. isomerization to the strong binding cause inappropriate α, β and γ state. Following this change, tropomyosin isoforms and inherited The Arg91Gly and Arg133Trp tropomyosin still covers an essential myopathies. Eight mutations in the mutations on the β tropomyosin part of the site, leaving it TPM1 gene induce amino acids isoform appear to preserve the inaccessible to myosin heads – the changes on the α tropomyosin 2+ closed state. Weak-to-strong myosin information from the Ca sensor, the isoform (Glu40Lys, Glu54Lys, Ala63Val, binding transition induces a second troponin complex to the cross­ Lys70Thr, Val95Ala, Asp175Asn, 2+ tropomyosin shift, permitting bridges. The Ca -activation of the Glu180Gly, Glu180Val), and are not cooperative binding of additional contractile proteins is unaltered as associated with skeletal myopathies myosin heads by exposing attested by the force-pCa but solely with cardiomyopathies. neighbouring sites – the open state. relationships (Ochala et al. 2007; Eight mutations in the TPM2 and Robinson et al. 2007) in contrast to TPM3 genes have been associated 9 γ Three major tropomyosin isoforms the Met Arg mutation on the with amino acids modifications on are expressed, α, β and γ, which are tropomyosin isoform where the β 91 117 133 encoded by the TPM1, TPM2, and the (Arg Gly, Glu Lys, Arg Trp, force-pCa curve was shifted to the 139 147 γ 9 TPM3 genes, respectively (Perry, Glu del, Glu Pro) and (Met Arg, right (Michele et al., 1999). The lack 2001). The α isoform encoded by Glu31stop, Arg167His) tropomyosin of effects of the Arg91Gly and TPM1 is predominantly expressed in isoforms and with general muscle Arg133Trp mutations on force-pCa cardiac and fast-twitch skeletal weakness and skeletal myopathies relationships is surprising but may be muscle fibres. The β isoform (Fig.1). related to their location in a region of encoded by TPM2 is mainly the tropomyosin segment that is not expressed in slow-twitch skeletal Recent studies approach the directly associated with the troponin muscle fibres. The γ isoform mechanisms by which three complex Ca2+ binding sites (Fig. 2). encoded by TPM3 is predominantly mutations in β (Arg91Gly, Arg133Trp) In skeletal muscle fibres, the critical expressed in cardiac and slow-twitch and γ (Met9Arg) tropomyosin interactions between tropomyosin skeletal muscle fibres. A number of isoforms cause general weakness in and troponin T take place between

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National Institutes of Health (AR045627, AR047318) to L L.

Julien Ochala1 Anders Oldfors2 Lars Larsson1, 3 1Department of Clinical Neurophysiology, Uppsala University Hospital, Sweden Figure 2. Tropomyosin segment. Troponin T (yellow) binds tropomyosin (red) in an 2Department of Pathology, overall anti-parallel manner, i.e. its C-terminal region is positioned near residue 190 of tropomyosin and the N-terminal tail of troponin T extends toward tropomyosin C­ Sahlgrenska University Hospital, terminus, overlapping the head to tail joint of tropomyosin as well as 10–30 residues Göteborg, Sweden of the N-terminus of the next molecule along the filament. 3Center for Development and Health Genetics, The Pennsylvania State tropomyosin residues 0–30 and thereby increasing the cross-bridge University, University Park, USA 190–284. The Arg91Gly and Arg133Trp detachment rate and maximum mutations on the β tropomyosin unloaded shortening velocity or References isoform are 60 residues away from maximal ATPase rates. The the nearest potential Troponin T­ combination of a decreased apparent Michele DE Albayya FP & Metzger JM (1999). A nemaline myopathy mutation in alpha­ anchoring region, in contrast to the rate of force redevelopment and an tropomyosin causes defective regulation of Met9Arg mutation on the γ increased maximum unloaded striated muscle force production. J Clin Invest tropomyosin isoform (Fig. 2) (Perry, shortening velocity in fibres 104, 1575-1581. 133 2001). expressing Arg Trp induces a Ochala J, Li M, Tajsharghi H, Kimber E, Tulinius shortened cross-bridge duty cycle, M, Oldfors A & Larsson L (2007). Effects of a The Arg91Gly and Arg133Trp i.e. a shorter time spent by myosin R133W beta-tropomyosin mutation on mutations on the β tropomyosin heads in a strongly bound force­ regulation of muscle contraction in single human muscle fibres. J Physiol 581, 1283­ isoform appear to directly modify generating state, resulting in a 1292. the cross-bridge kinetics as attested decreased force generating capacity. by the decreased maximal apparent Perry SV (2001). Vertebrate tropomyosin: rate constant of force redevelopment distribution, properties and function. J Muscle In conclusion, studies on the three Res Cell Motil 22, 5-49. and increased maximum unloaded Arg91Gly, Arg133Trp and Met9Arg shortening velocity in fibres mutations in β and γ tropomyosin Robinson P, Lipscomb S, Preston LC, Altin E, containing Arg133Trp (Ochala et al. Watkins H, Ashley CC & Redwood CS (2007). isoforms suggest specific Mutations in fast skeletal troponin I, troponin 2007) or increased maximal ATPase mechanisms underlying the T, and beta-tropomyosin that cause distal rates in fibres expressing Arg91Gly weakness, in the absence of muscle arthrogryposis all increase contractile (Robinson et al. 2007). The wasting, in patients carrying these function. Faseb J 21, 896-905. mutations from Arg to Gly or Arg to mutations. However, the Tajsharghi H, Kimber E, Holmgren D, Tulinius Trp replace charges predicted to mechanism is mutation-specific and M & Oldfors A (2007). Distal arthrogryposis stabilize tropomyosin coiled-coil results obtained from one mutation and muscle weakness associated with a beta­ (Tajsharghi et al. 2007). Therefore, cannot be generalized to other tropomyosin mutation. Neurology 68, 772­ 775. the Arg133Trp mutation may affect tropomyosin mutations. Further, the tropomyosin movement toward the results from these mutations inner domain of actin and the analyses indicate the critical role of Society Themed transition from the blocked state to tropomyosin isoform expression in the closed and open states. This modulating muscle contraction Meetings 2009 would disrupt attachment and/or under physiological conditions. The Society invites applications for transition of myosin heads from the meetings covering the following weakly to the strongly bound force­ Acknowledgements themes to be held in 2009: generating state, decreasing the The project was supported by grants • Cellular & integrative neuroscience cross-bridge attachment rate and from the Swedish Institute and • Human & exercise physiology the maximal apparent rate constant Association Française contre les • Epithelia & membrane transport of force redevelopment. Moreover, Myopathies to J O, from the 91 133 For further details, guidelines and the Arg Gly and Arg Trp mutations Association Française contre les an application form visit may affect tropomyosin movement Myopathies and Swedish Research http://www.physoc.org/meetings. from the open to the blocked state, Council (07122) to A O, and from the The deadline for the receipt of slowing myosin attachment and Swedish Research Council (08651), completed applications is 29 promoting dissociation of myosin Association Française contre les February 2008. heads from the actin filament; Myopathies, Cancer Foundation and

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Muscle’s silent sensors

This is a story about measurement of position sense at the elbow joint. If I cannot see my arm, where is it? The object of our studies has been to understand the changes in position sense seen after exercise and during loading of the arm. Our choice of the elbow joint is simply out of Figure 1. Position matching errors in the horizontal plane. Matching errors were o convenience. Some recent calculated as the difference in position between the reference arm, set at 85 , and the indicator arm placed by the blindfolded subject in a matching position. Errors were experiments using the knee scored as positive when the indicator was placed in an extended position relative to joint and the quadriceps muscle the reference arm, and negative when it was in the direction of flexion. Dotted line, have shown that the principles zero error. Red symbol, position errors (± SEM) for eight subjects when the reference arm had been conditioned in a flexed position (FC), while the indicator had been we have considered at the conditioned with the arm held extended (EC). Blue, symbol, errors when both arms elbow joint also applies at other had been flexion conditioned. Dashed line indicates the trend in the errors. joints. Data from Allen et al. (2007).

We have been using a property of muscle, called thixotropy, as a tool for investigating position sense (Physiology News 66, 20–22). Another word for thixotropy is muscle history-dependence. This is a method which allows us, at a given muscle length, to change the levels of background activity in muscle spindles of elbow muscles by contracting them while they are held short or long and then returning them to the initial length. Muscle spindles are believed to be largely responsible for signalling to the brain Figure 2. Position matching errors in the vertical plane after eccentric exercise. Blue muscle length and therefore elbow symbols, mean (± SEM) errors for six subjects when the reference arm was the angle. The changes in background exercised arm, red symbols when the indicator arm was the exercised arm. Errors activity following conditioning lead measured before, immediately after the exercise (0 h), at 20 h, 40 h, 60 h and 100 h. subjects to think that muscle length Data points have been joined by lines for clarity. Subjects held their arms, has changed and so they make errors unsupported. Errors were scored as positive when the indicator arm adopted a in limb position sense. position more extended that the reference. Errors were negative when it was more flexed. Dotted line, zero error. Data from Walsh et al. (2004). The way we have been doing the experiments is to use a position history effects in both arms. That has consistently placed their indicator matching task. The experimenter revealed an unexpected distribution arm in a position that was slightly places one forearm (reference) at a of position errors. For these more flexed (blue symbol) than the given angle and the subject is asked experiments, to avoid the effects of position adopted by the reference to match its position by placement of gravity, measurements were made in arm (dotted line). A second their other arm (indicator). One fact the horizontal plane. First, when observation made was that when the that emerged in recent experiments contraction history in both arms was reference arm was again flexion (Allen et al. 2007) is that it is made the same, unexpectedly, conditioned, but this time the necessary to consider the muscle position errors did not reduce to indicator arm had its elbow history-dependence of both zero. So, for example, in Fig. 1 when extensors contracted with the arm reference and indicator arms. both arms were conditioned by held extended (extension contracting elbow flexors with the conditioning), the subject thought In the recent experiments we began arms held flexed (flexion that their reference arm was much to systematically control for muscle conditioning), the subjects more extended that it really was (red

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that whenever the central nervous system generates activity in fusimotor neurons this is subtracted from the gross spindle discharge, to leave only the length-related signal to reach consciousness. Spindles are activated through the fusimotor system whenever we carry out a voluntary contraction. There are reasons for thinking that what is going on is more complicated than that. Here we were guided by some experiments on the effects of eccentric exercise on Figure 3. Position matching errors in the vertical plane. Values are means (± SEM) for position sense (Walsh et al. 2004). 12 subjects. Matching errors in the direction of extension are shown as positive. These experiments involved a Dotted line, zero error. For this experiment both arms had been flexion conditioned position matching task in the vertical before each matching trial. The four conditions for the reference arm were: plane. After eccentric exercise of one supported by the experimenter, supported by the subject, supported by the subject with a 10% maximum voluntary contraction load added, and supported by the arm this was weakened as a result of subject with a 25% load added (from Allen et al. 2007). the muscle damage and fatigue following the exercise (Proske & Morgan, 2001). When the exercised arm was the indicator, the subject made significant matching errors, placing it in a position that was more flexed than the position adopted by the reference arm (Fig. 2). Conversely, when the reference arm was fatigued matching errors lay in the direction of extension. To explain the result we proposed that when an arm was fatigued, it required more effort to hold it in a given position and the effort signal provided positional information. When the Figure 4. Position matching errors in the vertical plane after eccentric exercise. Each indicator was fatigued, the greater point is the mean (± SEM) value for 9 subjects. Before each match both arms had effort required to support its weight been flexion conditioned. Errors were scored as positive when the indicator arm was was interpreted as the arm being in a placed in the direction of extension relative to the reference, negative, when more extended position, where the placement was in the direction of flexion. Dotted line, zero error. Pre-exercise, values gravity vector acting on it was before the exercise; Post-exercise, values immediately after the exercise. Blue greater. So in making a match, symbols, when the exercised arm acted as the reference, red symbols, when the subjects flexed their indicator to a exercised arm acted as the indicator (from Allen et al. 2007). point where the effort signals in the symbol). In other words, by simply sensors during muscle contraction? two arms matched, leading to errors changing the form of conditioning of Muscle spindles, as stretch receptors, in the direction of flexion. the indicator arm, subjects believed are able to signal the length of a Predictably, errors reversed when it that arm position had shifted by over muscle. At the same time, because was the reference arm that had been 14o. These errors can be satisfactorily they have an inbuilt sensitivity exercised (Fig. 2). So we were explained by changes in background control, the fusimotor system, they proposing that during a muscle activity of muscle spindles of both are able to change their discharge contraction the errors in position arms, as a result of the thixotropic without any accompanying length sense arose from a new position property of their intrafusal fibres change. The problem was, how did signal derived from a centrally (Allen et al. 2007). That conclusion the central nervous system generated sense of effort. led us to pay a lot more attention to distinguish between activity arising the state of conditioning of the two from muscle length changes and A simple and direct test of the effort arms. from intrafusal contractions? hypothesis was to examine the effects of loading the arm by the An issue that has fascinated me for a The current accepted view is based addition of weights. Increasing the long time is the question, how can on a model put forward by load should increase the effort muscle spindles act as position McCloskey et al. (1983). The idea is required to support the arm and

Physiology News | No. 69 | Winter 2007 | www.physoc.org 24 PN FEATURES therefore produce position errors. fusimotor co-activation during feedback is present, but deprived of In this new experiment we were attempted movements would still be fusimotor activation? Will there be careful to make sure from the outset present and any subtraction from an negative effects this time? Whatever that for each trial both arms had absent afferent signal might have the outcome, there are two been conditioned identically. Then, been expected to lead to a negative important lessons from all of this. when one arm was loaded during the outcome, perceived movements in a One is that the effects of muscle match, position errors seen direction opposite to that which had thixotropy on muscle spindle previously (Winter et al. 2005) were been willed (Gandevia et al. 1993). discharges can lead to no longer present (Fig. 3). That was not the case. It led us to misinterpretation of observations on consider another explanation and limb position sense, and secondly, Presumably in the previous study the here we were attracted by we should not underestimate the observed errors had been thixotropy­ propositions involving an internal level of sophistication involved in the related. Subsequently we repeated forward model (Bays & Wolpert, central processing of proprioceptive the experiment on eccentric 2007). information. exercise, again making sure that both arms had first been identically The idea is simple enough. As soon Uwe Proske conditioned. (Fig. 4). When the as a voluntary contraction of arm Trevor Allen reference arm had been exercised, muscles accompanies the Department of Physiology, Monash error lay in the direction of movement, or maintained position, University, Clayton, Victoria, extension. When the indicator was an efference copy of the motor Australia exercised they lay in the direction of command signal to the muscle flexion (Allen et al. 2007). This was becomes available. The efference the same pattern as reported by copy accesses memory stores of References Walsh et al. (2004), but now we were similar movements carried out in the Allen TJ, Ansems GE & Proske U (2007). Effects no longer invoking the sense of past to compare the afferent of muscle conditioning on position sense at the human forearm during loading or fatigue effort as responsible for the errors. If feedback that had accompanied of elbow flexors and the role of the sense of effort had played a significant role it those movements with the feedback effort. J Physiol 580.2, 423–434. should have shown up in the during the present movement. Only experiments of loading the arm, the difference signal reaches Bays PM & Wolpert DM (2007). Computational which it did not. consciousness. When the anticipated principles of sensorimotor control that minimize uncertainty and variability. J Physiol and fed-back signals are the same, 578, 387–396. How do we explain all of this? the posture is confirmed with no Sticking to the simple result of Fig. 3, accompanying sensation of a change Gandevia SC, Killian K, McKenzie DK, Crawford the conclusion is reached that in the in position, thus the label of muscle M, Allen GM, Gorman RB & Hales JP (1993). absence of vision we are able to Respiratory sensations, cardiovascular control, receptors as ‘silent sensors’. kinaesthesia and transcranial stimulation locate, equally accurately, the during paralysis in humans. J Physiol 470, position of our arms, whether they Finally, it is necessary to explain the 85–107. are loaded or not, provided that effects of exercise. We have now beforehand they have been done exercise experiments on both Gandevia SC, Smith JL, Crawford M, Proske U & conditioned identically. So, by Taylor JL (2006). Motor commands contribute arm muscles and leg muscles. The to human position sense. J Physiol 571, inference, whether arm muscles are interpretation that is consistent with 703–710. contracting or not does not alter our all of the observations is that we sense of forearm position. Given that perceive an exercised muscle as McCloskey DI, Gandevia SC, Potter EK & during voluntary contractions the longer than it actually is. For the Colebatch JG (1983). Muscle sense and effort: fusimotor neurons are co-activated, motor commands and judgements about arm, when the elbow flexors have muscular contractions. In Motor Control the result could be interpreted as been exercised, the arm is perceived Mechanisms in Health and Disease, ed. evidence in support of the operation as more extended (longer flexors) Desmedt JE, pp. 151–167. Raven Press, New of the McCloskey et al. (1983) than is really the case. Our York. subtraction model. interpretation, in terms of the Proske U & Morgan DL (2001). Muscle damage operation of an internal forward from eccentric exercise: mechanism, But there were bits of evidence model, is that the afferent feedback mechanical signs, adaptation and clinical which did not quite fit such an for maintenance of a given position is applications. J Physiol 537, 333–345. interpretation. Experiments on the higher, as a result of fatigue, and that Walsh LD, Hesse CW, Morgan DL & Proske U paralysed, anaesthetised arm had is interpreted as a longer muscle. (2004). Human forearm position sense after shown that a large position signal of fatigue of elbow flexor muscles. J Physiol 558, central origin was available when We are now on the lookout for 705–715. peripheral afferent activity had been experiments that will test the blocked (Gandevia et al. 2006). Winter JA, Allen TJ & Proske U (2005). Muscle forward model hypothesis more spindle signals combine with the sense of Presumably with such a block in directly. What happens when the effort to indicate limb position. J Physiol 568, place, the command signals for muscle is paralysed, that is, afferent 1035–1046.

Physiology News | No. 69 | Winter 2007 | www.physoc.org Physiology News | No. 68 | Autumn 2007 | www.physoc.org FEATURES PN 25

The pattern of intracellular Ca2+ signal matters in epithelial secretion Endocrine and exocrine cells respond to external cues by releasing different secretory molecules. Seung-Ryoung Jung and colleagues analyzed how ductal epithelia encode the external inputs into Ca2+ signals and decode them into specific types of secretion

Calcium regulates many cellular processes including muscle contraction, fertilization, gene expression, membrane excitability, and exocytosis (Berridge et al. 2003). To modulate a variety of target molecules selectively in a cell, the Ca2+ signal itself has to carry discriminatory information. Sometimes selectivity is achieved by subcellular localization of the signal, and sometimes by the pattern of the signal. In electrically excitable cells, Duk-Su Koh (left), Bertil Hille, Toan Nguyen, and Seung-Ryoung Jung Ca2+ signals are typically determined 2+ (PDEC) lining the ducts add an by the activity of voltage-gated Ca2+ oscillations of [Ca ]i, where agonist important component to the channels that mediate Ca2+ fluxes concentration determines the digestive fluid, HCO – (bicarbonate), from the extracellular space into the frequency of oscillations 3 cytoplasm. In non-excitable cells (‘frequency’ modulation, FM). The which neutralizes acidic chyme from equipped with G-protein coupled oscillation frequency seems to have a the stomach. Bicarbonate secretion significant role in modulating gene from PDEC is mediated by ion receptor (GPCR)-linked IP3 expression (Dolmetsch et al. 1998) channels and transporters (Nguyen generation, Ca2+ is often mobilized and certain enzymes, including Ca2+­ et al. 1998). In addition, the cells from internal stores by external dependent intramitochondrial secrete mucin, a major protein of the agonists. The detailed time course of dehydrogenases and protein kinase C mucus layer, via exocytosis (Nguyen cytoplasmic free Ca2+ concentration (Hajnóczky et al. 1995; Oancea & ([Ca2+] ) is further modified by Ca2+ i Meyer, 1998). In general, these Ca2+­ binding proteins and by dependent enzymes are partially 2+ transmembrane movements of Ca activated by each Ca2+ spike and then ions between the cytoplasm, deactivated slowly as Ca2+ declines. If intracellular stores, other organelles, the next Ca2+ spike occurs before the and the extracellular space. Ca2+ enzyme is fully deactivated, there is a signals generated by GPCRs are often cumulative increase of enzyme encoded as a graded increase of 2+ activity. [Ca ]i, with higher concentrations of agonists eliciting higher peak Pancreatic ducts collect digestive 2+ amplitudes of [Ca ]i (‘amplitude’ enzymes released from acinar cells, modulation, AM). In addition, a delivering them to the duodenum. signal can be conveyed by Pancreatic duct epithelial cells

– Figure 1. Differential effects of purinergic input on HCO3 secretion and exocytosis in pancreatic duct epithelial cells. A, Exocytosis rates measured with microamperometry and normalized to the baseline value. Exocytosis induced by 2, 10, and 100 mM UTP is denoted as +2 (filled triangle), +10 (open circle), and +100 (filled square), 2+ respectively. B, UTP (10 mM) enhances [Ca ]i oscillations (measured with fura-2) and Ca2+-activated K+ current (measured simultaneously by whole-cell patch-clamp). C, UTP hyperpolarizes the membrane potential. The hyperpolarization was sensitive to charybdotoxin (CTX), a blocker of Ca2+-activated K+ channel (data not shown). – D, UTP enhances HCO3 secretion measured with a pH-sensitive dye (BCECF). The – intracellular compartment was first alkalinized by removing external HCO3 and then – the intracellular pH (pHi) was allowed to recover through secretion of HCO3 . The rate – of the pHi decrease (DpHi/Dt) during the reacidification, a measure of HCO3 secretion, is expressed relative to the rate seen in the absence of agonist. Modified from Jung et al. (2006).

Physiology News | No. 69 | Winter 2007 | www.physoc.org 26 PN FEATURES et al. 1998). Previous studies using PDEC monolayers demonstrated that 2+ [Ca ]i elevations, induced by endogenous purinergic receptors

(P2Y2 and P2Y11) promote both electrolyte (K+ and Cl–) and mucin secretion (Nguyen et al. 1998). However, the single-cell Ca2+ dynamics were not resolved in those studies which used populations of PDEC. Our recent single-cell measurements reveal a complex Ca2+ signaling system that depends on the agonist concentration: a low Figure 2. Transduction of stimuli into secretion in pancreatic duct epithelial cells. Low 2+ concentration of ATP or UTP (2 or 10 concentrations of UTP evoke [Ca ]i oscillations, and high concentrations of UTP 2+ induce a persistent [Ca2+] rise. The oscillatory Ca2+ signal causes HCO – secretion by µM) evokes [Ca ]i oscillations (Fig. i 3 1B), whereas a high concentration of activating Ca2+-activated K+ channels and hyperpolarizing the membrane. The 2+ – ATP or UTP (100 µM) evokes a persistent [Ca ]i rise elicits both HCO3 secretion and exocytosis of proteins including 2+ mucin. sustained [Ca ]i elevation (Jung et al. 2004, 2006). As measured with single-cell microamperometry, the high (100 µM) concentrations of UTP mucin secretion as well. These 2+ – differential responses would be sustained [Ca ]i elevation stimulated stimulated HCO3 secretion to a particularly relevant to the emerging exocytosis well, but the [Ca2+] similar extent, showing the i autocrine and paracrine function of oscillations were much less equivalence of oscillatory and 2+ ATP, the major physiological efficacious (Fig. 1A), despite reaching sustained [Ca ]i increases in activator of these receptors. The 2+ µ modulating HCO – secretion (Fig. similar peak [Ca ]i levels (1-2 M). 3 extracellular concentration of ATP – 1D). Further, the UTP effect on HCO3 depends on ATP release, diffusion, 2+ What is the role of oscillatory Ca secretion was fully blocked by an IK dilution, and local metabolism. signals? We tested the hypothesis channel blocker, charybdotoxin, Further investigation should show that Ca2+ oscillations open Ca2+­ suggesting that the K+ channel and whether other receptors coupled to + – activated K and Cl channels its hyperpolarizing effect are Gq and PLC (e.g. histamine H1, – expressed in PDEC. Both channels essential for HCO3 secretion. The protease activated (PAR-2), should be activated by micromolar underlying mechanism(s) for the muscarinic, or cholecystokinin 2+ levels of Ca . As anticipated, – electrogenic HCO3 secretion is not receptors) alone or in combination electrophysiological studies in the yet clear. The hyperpolarization elicit similar responses. whole-cell patch configuration – + could favor a lower intracellular Cl revealed a periodic activation of K concentration that would accelerate Physiological significance of the channels synchronous with the the activity of Cl–/HCO – exchanger ductal input-output relations [Ca2+] oscillations (Fig. 1B) and 3 i indirectly. Alternatively, the Along with neutralization of acidic – periodic hyperpolarizations of the hyperpolarization could increase chyme, the ductal HCO3 probably membrane (Fig. 1C). We identified HCO – efflux through HCO –­ also alters the rheologic properties the channel as a Ca2+-activated K+ 3 3 permeable anion channels directly. of mucin secreted from the duct channel of intermediate An argument in favor of the cells. The viscosity of mucin tends to conductance (IK1/SK4 subtype) – – increase at acidic pH. If secretion of Cl /HCO3 exchanger was that – using pharmacology, single-channel HCO3 is impaired, as in cystic recording, and immuno­ blocking it with DIDS or by removing – fibrosis, the luminal pH would fall histochemistry. Finally, we reasoned external Cl eliminated the effect of – and mucin released from PDEC might that the hyperpolarization might UTP on HCO3 secretion. become more viscous and not be – accelerate secretion of HCO3 . cleared from the epithelial surface. Bicarbonate secretion from single In summary, the intensity of external Formation of a mucin gel in the cells was assayed indirectly using a stimuli can be encoded into different pancreatic ductal tree could lead to 2+ pH-sensitive dye (BCECF). A higher patterns of [Ca ]i increases, to be the blockage of the small ducts and rate of intracellular pH decrease decoded later into different eventual destruction of the gland. ∆ ∆ – ( pHi/ t) should reflect increased biological outputs (Fig. 2). Low We therefore suggest that HCO3 and – HCO3 efflux from the cytoplasm to concentrations of purinergic agonists mucin secretion need to be well – the extracellular compartment. We evoke mainly HCO3 secretion, balanced. As UTP analogues have found that low (2 and 10 µM) and whereas high concentrations evoke been advocated in the clinical

Physiology News | No. 69 | Winter 2007 | www.physoc.org FEATURES PN 27 treatment of cystic fibrosis, our β-adrenergic receptor desensitisation – a findings suggest that low concentrations may be preferable to mechanism for post-exercise reductions in high concentration of these agents – cardiac function as they may increase HCO3 secretion through activation of IK channels It is widely recognised that skeletal while stimulating less mucin muscle performance is reduced in production. response to prolonged exercise; whether the same occurs with 1 Seung-Ryoung Jung cardiac muscle is currently a topic of Toan D Nguyen1,3 scientific debate. A number of recent Bertil Hille2 studies have demonstrated a modest and transitory impairment of left 2,4 Duk-Su Koh ventricular (LV) systolic (ejection Departments of 1Medicine and fraction and the ratio of end systolic 2Physiology and Biophysics, volume to pressure) and diastolic University of Washington, Seattle, (ratios of early to late LV filling and WA, USA, early and late myocardial wall velocities) function after prolonged 3VA Puget Sound Health Care exercise such as marathon running Keith George (left), Emma Hart and Rob System, Seattle, USA and Ironman triathlons. Shave. 4Department of Physics, POSTECH, Korea Driven largely by advances in reductions in both global and echocardiographic technology, regional diastolic function has been References numerous studies have described presented (Neilan et al. 2006). The Berridge MJ, Bootman MD & Roderick HL post-exercise cardiac impairment in trans-mitral filling ratio and LV flow (2003). Calcium signalling: dynamics, increasing detail. The initial studies propagation velocity has been shown homeostasis and remodelling. Nat Rev Mol Cell Biol 4, 517–529. using 2-dimensional and Doppler to be transiently impaired post­ measures were improved upon with exercise (Fig. 2). These global Dolmetsch RE, Xu K & Lewis RS (1998). tissue Doppler and recently 2­ diastolic changes have been mirrored Calcium oscillations increase the efficiency dimensional speckle tracking. With by segmental reductions in diastolic and specificity of gene expression. Nature 392, 933–936. the advance in technology it has wall velocities, strain and strain rate been possible to demonstrate both (George et al. 2006; Neilan et al. Jung SR, Kim MH, Hille B, Nguyen TD & Koh DS global and regional changes in 2006). (2004). Regulation of exocytosis by purinergic , receptors in pancreatic duct epithelial cells. systolic function; for example Rifai Am J Physiol 286, C573–579. et al. (1999) demonstrated a 21% It is important to recognise the reduction in ejection fraction in limitations of some of the echo­ Jung SR, Kim KJ, Hille B, Nguyen TD & Koh DS addition to segmental wall motion cardiographic techniques that have 2+ (2006). Pattern of Ca increase determines abnormalities. More recently our been employed; trans-mitral the type of secretory mechanism activated in dog pancreatic duct epithelial cells. J Physiol group have demonstrated regional Doppler, flow propagation velocity 576, 163–178. reductions in peak systolic 2D and ejection fraction are highly derived strain and strain rate dependent upon loading and heart Nguyen TD, Moody MW, Savard CE & Lee SP (longitudinal, circumferential and rate. Accordingly, assessment of (1998). Secretory effects of ATP on nontransformed dog pancreatic duct radial planes) in athletes completing these variables pre- to post- exercise epithelial cells. Am J Physiol 275, G104–113. the Comrades ultra-marathon warrants caution; however, the (Fig. 1). Similarly, evidence for regional differences in LV function Hajnóczky G, Robb-Gaspers LD, Seitz MB & Thomas AP (1995). Decoding of cytosolic calcium oscillations in the mitochondria. Cell 82, 415–424.

Oancea E & Meyer T (1998). Protein kinase C as a molecular machine for decoding calcium and diacylglycerol signals. Cell 95, 307–318.

Acknowledgement Apologies to Martin Rosenberg for Figure 1. Individual example of peak radial strain pre- (A) and post- (B) completion of failing to acknowledge his award­ the Comrades ultra-marathon. Note the reduction in peak strain in the septal and winning photograph of Sir Eric anteroseptal wall segments but the almost identical pre and post-race peak strain Denton (Physiology News 67, 55). values in free wall segments.

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release of highly cardiac specific markers of injury e.g. cardiac troponin T, impaired sequestration and re-uptake of calcium into the sarcoplasmic reticulum and de­ sensitisation of the β-adrenergic receptors (β- AR). To date, however, empirical evidence supporting a role for any of these mechanisms is limited.

In our recent study we employed pharmacological manipulation to examine the role of β-AR in post­ exercise changes in cardiac function (Hart et al. 2006). Prior to and Figure 2. Individual example of trans-mitral Doppler profiles pre- (A) and post- (B) following a 4 h bout of rowing completion of the London marathon, note the reduction in early and increase in late exercise we examined the systolic filling velocity. and diastolic response to increasing doses of isoproterenol (a β-AR that have been shown cannot be function is useful it does not provide agonist). In order to partition out explained by altered loading or HR. a mechanistic explanation. pre- to post-exercise changes in Further, when correlations are vagal tone, glycopyrrolate (a examined the changes in LV function A number of possible mechanisms parasympathetic blocking agent) following prolonged exercise cannot for post-exercise changes in LV was administered prior to β-AR be fully explained by altered loading function have been suggested – stimulation. Our data demonstrate or HR. Whilst characterisation of including minor injury to the that there is a reduction in the post-exercise alterations in LV myocardium evidenced by the chronotropic and inotropic response to β-AR stimulation following 4 h of rowing (Fig. 3). We suggest, therefore, that post-exercise reductions in systolic function are likely related to a de-sensitisation of the β-AR.

Within heart failure patients, a clear link has been demonstrated between elevations in circulating catechola­ mines and de-sensitisation and down-regulation of the β-AR (Dzimi et al. 1999). It is possible that a similar mechanism may occur following prolonged exercise. Of interest, those participants within our study that demonstrated the greatest elevation in adrenaline following exercise also demonstrated the largest reduction in LV contractility as assessed by ejection fraction (r2=0.96, P<0.05).

The cardiac β-AR subtypes β1 and β2 activate different signalling Figure 3. Left ventricular response to incremental isoproterenol infusion pre- and pathways within the myocyte (Xiao post-exercise. Inotropic (A), lusitropic (B) and chronotropic/ loading (C) response to et al. 2004). It is possible that during isoproterenol pre- (continuous line) and post-exercise (dashed line). Data are means ± prolonged exercise the sustained SD. Q, cardiac output; SV, stroke volume; EF, ejection fraction; SBP/ESV, systolic blood pressure to end systolic volume ratio; Vp, flow propagation velocity of early elevations in catecholamines initiates β transmitral filling; A, peak velocity of late transmitral filling; E/A, ratio of early to late 1-AR mediated apoptosis of the LV filling; MAP, mean arterial pressure; LVMWS, LV meridonial wall stress; LVIDd, LV myocyte (Rohrer et al. 1999) which internal diameter in diastole; HR, heart rate. Different from pre-exercise *p< 0.05, may increase membrane **p <0.01 (from Hart et al. 2006). permeability and hence explain the

Physiology News | No. 69 | Winter 2007 | www.physoc.org FEATURES PN 29 release of cardiac biomarkers such as post-exercise changes in LV function JE, Halpern EF, Lawlor D, Picard MH, & Wood cardiac troponin T observed translate to a cardiac limitation MJ. (2006). Persistent and reversible cardiac dysfunction among amateur marathon following prolonged exercise. during prolonged exercise and runners. Eur Heart J 27, 1079-1084. Conversely, stimulation of the β2-AR whether β-AR de-sensitisation is has an anti-apoptotic effect and related to LV hypertrophy remains to Patterson AJ, Zhu W, Chow A, Agrawal R, Kosek J, Xiao RP, et al. (2004). Protecting the protects the myocyte against injury be elucidated. myocardium: A role for the beta2 adrenergic (Patterson et al. 2004). Accordingly, receptor in the heart. Crit Care Med 32, 1041­ 1 de-sensitisation of β1-AR and Rob Shave 1048. β 2 stimulation of 2-AR during Keith George Rifai N, Douglas PS, O'Toole M, Rimm E, & prolonged exercise may occur so as 1 Ginsburg GS. (1999). Cardiac troponin T and I, to limit injury to the myocardium. In Emma Hart echocardiographic [correction of 1 order to examine the role of the Centre for Sports Medicine and electrocardiographic] wall motion analyses, β Human Performance, Brunel and ejection fractions in athletes participating specific -AR subtypes further work in the hawaii ironman triathlon. Am J Cardiol is required. University, Uxbridge, Middlesex, UB8 83, 1085-1089. 3PH Over stimulation of the β-AR has Rohrer DK, Chruscinski A, Schauble EH, 2Research Institute for Sport and been demonstrated to induce Bernstein D, & Kobilka BK. (1999). Exercise Sciences, Liverpool John Cardiovascular and metabolic alterations in hypertrophy, at least in the rat heart Moores University, Liverpool, L3 2ET mice lacking both beta1- and beta2­ (Schafer et al. 2000). Therefore, the adrenergic receptors. J Biol Chem 274, 16701­ sustained exposure of the β-AR to 16708. References catecholamines during prolonged Dzimiri N. (1999). Regulation of beta­ Sato M, Gong H, Terracciano CM, Ranu H, & exercise may also be an initial adrenoceptor signaling in cardiac function and Harding SE. (2004). Loss of beta-adrenoceptor stimulus for LV hypertrophy often disease. Pharmacol Rev 51, 465-501. response in myocytes overexpressing the reported in endurance trained Na+/Ca(2+)-exchanger. J Mol Cell Cardiol 36, athletes. This, however, remains George K, Oxborough D, Forster J, Whyte G, 43-48. Shave R, Dawson E, Stephenson C, Dugdill L, unsubstantiated and warrants Edwards B, & Gaze D. (2005). Mitral annular Schafer M, Frischkopf K, Taimor G, Piper HM, further research. myocardial velocity assessment of segmental & Schluter KD. (2000). Hypertrophic effect of left ventricular diastolic function after selective beta(1)-adrenoceptor stimulation on Although desensitisation of β-AR prolonged exercise in humans. J Physiol 569, ventricular cardiomyocytes from adult rat. Am 305-313. J Physiol Cell Physiol 279, C495-503. may be responsible for the reductions in LV systolic function Hart E, Dawson E, Rasmussen P, George K, Xiao RP, Zhu W, Zheng M, Chakir K, Bond R, post-exercise it is interesting to note Secher N, Whyte G, Shave R. (2006) b­ Lakatta EG, & Cheng H. (2004). Subtype­ that the diastolic response to adrenergic receptor desensitization in man: specific beta-adrenoceptor signaling pathways insight into post-exercise attenuation of in the heart and their potential clinical increasing doses of isoproterenol did cardiac function. J Physiol 577, 717-725. implications. Trends Pharmacol Sci 25, 358­ not alter following four-hours of Neilan TG, Yoerger DM, Douglas PS, Marshall 365. rowing (Fig. 3). Accordingly, changes in diastolic function observed following prolonged exercise are Tennis and transmission likely related to a different J C Eccles has been the subject of myriad anecdotes. Fragments of the mechanism. Previous studies have following one have been lurking in my memory since I heard it at the IUPS indicated that in some chronic heart Meeting in Sydney in 1983. Liam Burke has confirmed it and added some failure models, β-AR de-sensitisation background detail. is related to systolic but not diastolic dysfunction due to an up-regulation Eccles was a very keen tennis player and had a tennis court at his house in of the sodium-calcium exchanger Mosman when he was Director of the Kanematsu Research Institute in Sydney. (Sato et al. 2004). Consequently, Bernard Katz and Stephen Kuffler both lived in Mosman and it was traditional calcium is removed from the for them to meet for tennis at Eccles' house on Sundays. Apparently a major reason why Eccles had hired Kuffler (who had no research experience) was myocyte maintaining diastolic because he was a good tennis player. (He had been the Austrian Junior Tennis function, in spite of an impaired Champion before fleeing the Nazis.) Eccles always liked to keep people systolic function. Whether this is involved and busy so, on one occasion, he gave Katz the job of mowing the relevant in the prolonged exercise lawn. Katz, who may never have used an electric mower before, ran over the model is not clear. flex and almost electrocuted himself. Eccles immediately acquired a petrol­ driven mower. According to Katz, and very typical of his sense of humour, this The present study provides a was the moment when Eccles was converted from electrical transmission to mechanistic insight into post­ chemical transmission (at least in the peripheral nervous system). exercise alterations in LV systolic function; however, the mechanisms Perhaps other ageing physiologists have more Eccles stories to tell. for alterations in diastolic function Ann Silver following prolonged exercise are not Honorary Member, Cambridge fully understood. Further, whether

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ATP synthesis during ischaemic muscle contractions he integrity and function of skeletal the action of three major pathways intracellular ATP stores during muscle cells depend upon an that provide ATP at a rate that ischaemic muscle contractions adequate supply of adenosine satisfies the energetic demands of compared to contractions with triphosphate (ATP). In contracting muscle across a range of conditions intact blood flow. However, work skeletal muscle, ATP is consumed at (Fig. 1). from our laboratory (Lanza et al. three major sites: 2006) and others (Hogan et al. 1996) The ability to generate ATP has shown that cytosolic [ATP] •Na+-K+ ATPase, which restores the oxidatively becomes compromised remains unchanged during free-flow electrochemical gradient across under conditions of limited oxygen and ischaemic contractions, the muscle membrane following delivery or decreased functionality of suggesting that skeletal muscle has a depolarization; mitochondria. Clinically relevant strategy for balancing ATP supply examples of these conditions include and demand even when the • actin-myosin ATPase, which peripheral vascular disease and mitochondria are rendered incapable consumes ATP during crossbridge mitochondrial myopathy, both of of generating ATP. cycling in the process of force which are characterized by impaired generation; and oxidative ATP synthesis. Much Does skeletal muscle compensate by research has been dedicated to increasing ATP production through • sarcoplasmic reticulum (SR) understanding how ATP synthesis is other synthesis pathways, for ATPase, which is responsible for affected by limitations in oxygen example anaerobic glycolysis? This calcium resequestration into the supply and delivery to working response is biochemically intuitive, SR during muscle relaxation. skeletal muscle. Studies of healthy since several substrates involved in human skeletal muscle under the reduction of pyruvate to lactate Skeletal muscle has a limited storage hypoxic or ischaemic conditions have (e.g. pyruvate, NADH) will capacity for ATP, which is somewhat provided some insight into the accumulate in the muscle if surprising given how crucial ATP is to energetic response to conditions in mitochondrial flux is inhibited. cellular function. For example, which oxidative phosphorylation is Although the reduction of pyruvate during intense muscle contractions, impaired. to lactate is not itself an ATP­ where the consumption of ATP generating step in anaerobic increases ~100-fold compared to One could anticipate that if oxidative glycolysis, increased lactate rest, the ATP reserve would be phosphorylation is suppressed, then production may indirectly help drive exhausted in a matter of seconds. intracellular ATP stores might be upstream reactions by maintaining a Remarkably, intracellular ATP depleted during contractions if the high cytosolic NAD+/ NADH ratio. concentration remains stable even demand for ATP exceeds the supply Phosphorous magnetic resonance after several minutes of maximum­ from non-oxidative pathways. Some spectroscopy (31P-MRS) is an ideal intensity muscle contractions. This research supports this notion by tool for addressing questions related phenomenon can be explained by demonstrating depletion of to muscle ATP production in vivo, as it is a non-invasive technique that allows quantification of ATP synthesis with a temporal resolution unmatched by more traditional techniques, such as muscle biopsy analyses (Kemp et al. 1994). This approach has been used to examine ATP synthesis in maximally­ contracting skeletal muscle under free-flow conditions and with blood flow occluded (Conley et al. 1998; Lanza et al. 2006). In both of these studies, glycolytic flux did not increase during ischaemia, dispelling the notion, at least during brief maximal contractions with acute Figure 1. During muscle contractions, ATP demand by the ATPases is generally ischaemia, that glycolytic ATP matched by ATP synthesis through three major metabolic pathways. The creatine synthesis compensates for acute kinase reaction phosphorylates adenosine diphosphate (ADP) to ATP at the expense limitations in mitochondrial ATP flux. of phosphocreatine (PCr). ATP is also produced via oxidative phosphorylation in the Alternatively, the balance between mitochondria and by anaerobic glycolysis in the cytosol. ATP supply and demand may be met

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Figure 2. ATP production from oxidative phosphorylation (ATPOX, A), anaerobic glycolysis (ATPGLY, B), and net PCr 31 hydrolysis (ATPCK, C) measured by P- MRS in human tibialis anterior muscle during free-flow (•) and ischaemic (o)contractions. Total ATP turnover

(ATPTOT, D), calculated as the sum of

ATPOX, ATPGLY, and ATPCK, was greater during free-flow compared to ischaemia.

by decreasing demand for ATP rather than with a compensatory increase in ATP supply through an alternative pathway (Lanza et al. 2006). At least two mechanisms by which ATP demand may decrease during contractions in oxygen-limited conditions have been proposed (Hogan et al. 1996; Lanza et al. 2006).

First, the demand for ATP may be tempered by increased contractile economy (force produced per unit of ATP consumed) when oxygen levels are not adequate to sustain oxidative metabolism. Using 31P-MRS measures of ATP synthesis rates (Figs. 2A, B, C), along with simultaneous measures of muscle force production, we found that contractile economy was higher in vivo during ischaemic compared with free-flow contractions in human skeletal muscle (Fig. 2D; Lanza et al. 2006). Using more invasive measures of blood flow, peripheral oxygen uptake, and ATP production,

Figure 3. Mean muscle oxygen uptake (A) and force production (B) during control contractions (open circles, o) and during contractions with step reductions in oxygen delivery elicited either by decreasing the fraction of inspired oxygen (hypoxia, open triangles, ∆) or lowering pump perfusion of the muscle (ischaemia, filled circles, •). (A) Following

an initial rise in VO2, oxygen uptake remained constant during control contractions, whereas contractions during ischaemia and hypoxia elicited

similar declines in VO2 as contractions progressed, in comparison to control. (B) Developed force remained constant during control contractions, but steadily decreased during ischaemic and hypoxic contractions, with a greater decline during ischaemia than hypoxia by minutes 18 and 21. (Reproduced from Hogan et al. (1996), with permission.)

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Krustrup et al. (2003) found higher tissue. Preconditioning heart muscle mechanical efficiency and lower heat with brief bouts of ischaemia leads to Sydney Ringer production during ischaemia than decreased ATP demand in concert when blood flow was intact. Thus, with reduced ATP production during there exists in vivo and in situ subsequent bouts of prolonged Image evidence to support the greater ischaemia. This phenomenon, known based on a photo by economy of ischaemic compared to as ‘myocardial hibernation’, can Lisa Inoue of oxygenated contractions. Numerous reduce subsequent infarct size by Tokyo factors could contribute to increased preventing severe disruptions in (1991), who contractile economy in the absence cellular homeostasis. The work of draws of adequate oxygenation; for Hogan and others suggests that inspiration from example, changes in intracellular pH, skeletal muscle is also capable of this Ringer’s life calcium, temperature, and free type of behaviour. and work. phosphate have all been suggested to affect contractile economy, In summary, it appears that skeletal David Miller, Honorary Research possibly through direct effects on muscle is adept at ensuring a balance Fellow at the Faculty of Biomedical the rate of cross-bridge cycling. between energy supply and demand & Life Sciences, University of under a variety of conditions, Glasgow, has produced A solution In addition to the metabolic savings including situations where limited for the heart: the life of Sydney conferred by increased contractile oxygen delivery precludes oxidative Ringer (1836–1910). economy during ischaemia, the synthesis of ATP. Although Ringer is the scientist and clinician demand for ATP may also decrease compensatory increases in non­ most properly credited with consequent on the greater muscle oxidative ATP production seem ‘inventing’ physiological saline, fatigue during ischaemic compared logical, the results from several most familiar as the ‘drip’ seen in to free-flow contractions. As studies suggest that this does not operating theatres and hospital contractility declines during fatigue, occur in vivo. Instead, an energetic wards. As one of the scientific so too does the amount of ATP balance appears to be accomplished fathers of this life-saving liquid, required by the ATPases, particularly by decreasing ATP demand during Ringer deserves to be as well myosin ATPase. It has been contractions, potentially by known as others whose names are suggested that this may serve as a increasing contractile economy or associated with the great protective mechanism designed to decreasing force production. advances of medical science. prevent declines in cellular (ATP) and Ian R Lanza disruption of cellular homeostasis. David’s booklet tells about a Under ischaemic conditions, greater Jane A Kent-Braun remarkable scientist and doctor fatigue may develop due to the Muscle Physiology Laboratory, who was associated with the accumulation of intracellular Department of Kinesiology, village of Lastingham in North + - metabolites (H , Pi, H2PO4 ) that are University of Massachusetts, USA Yorkshire and its church for most known to interfere with sarcolemmal of his adult life. Sydney Ringer lies excitability, calcium handling by the References buried in the churchyard of St SR, and myofibrillar force generation. Conley KE, Kushmerick MJ & Jubrias, SA Mary’s, Lastingham, North However, there are some intriguing (1998). Glycolysis is independent of Yorkshire, together with his wife data to suggest that, under certain oxygenation state in stimulated human skeletal muscle in vivo. J Physiol 511, 935–945. and their elder daughter, in whose conditions, force production is memory the church was tightly coupled to oxidative ATP Hogan MC, Kurdak SS & Arthur, PG (1996). extensively restored in 1879. It supply. Hogan and colleagues Effect of gradual reduction in O2 delivery on intracellular homeostasis in contracting gives some insight into life in demonstrated this concept nicely in skeletal muscle. J Appl Physiol 80, 1313–1321. Lastingham in the 19th century and a perfused dog muscle preparation Ringer’s career as a leading by imposing gradual, stepwise Kemp GJ, Thompson CH, Barnes PR, & Radda London medical man of his day. reductions in oxygen delivery and GK (1994). Comparisons of ATP turnover in human muscle during ischemic and aerobic A plaque in honour of Sydney observing that force production exercise using 31P magnetic resonance decreased in parallel with declines in spectroscopy. Magn Reson Med 31, 248–258. Ringer, sponsored by The muscle VO2 (Hogan et al. 1996; see Physiological Society, was Fig. 3A, B). Furthermore, this Krustrup P, Ferguson RA, Kjaer M, & Bangsbo J unveiled by Dafydd Walters at St (2003). ATP and heat production in human Mary’s on 27 October. Photos of response occurred in the absence of skeletal muscle during dynamic exercise: any differences in muscle lactate higher efficiency of anaerobic than aerobic the occasion will be published in a production, ATP depletion, or ATP resynthesis. J Physiol 549, 255–269. future issue of Physiology News. accumulation of inhibitory Lanza IR, Wigmore DM, Befroy DE, & Kent- Copies of the booklet are available at metabolites. This behaviour in Braun JA (2006). In vivo ATP production during http://www.physoc.org/about/history skeletal muscle is similar to that free-flow and ischaemic muscle contractions or in print via [email protected]. observed repeatedly in cardiac in humans. J Physiol 577, 353–367.

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Colonic elongation activates an intrinsic reflex that underlies slow transit and accommodation It is generally believed that after-hyperpolarizing neurons are the only intrinsic sensory neurons in the gut wall. Recently, Smith and colleagues have demonstrated that some synaptic interneurons in the large bowel are activated by circumferential stretch and generate an ongoing motor activity even when AH neurons are silent. Further studies suggest that some descending interneurons are also mechanosensory since they are activated by longitudinal stretch rather than circumferential stretch. In particular, these mechanosensory neurons, which are NOS positive, respond to colonic elongation by releasing nitric oxide to reduce activity in intrinsic peristaltic circuits. This later reflex promotes storage by reducing the transit rate of fecal pellets down the large bowel

Transit of intraluminal contents the proximal and distal colon (NO) within myenteric neurons has through the human large bowel is (D’Antona et al. 2001). been proposed from immuno­ extremely slow ( ≥ 30 hrs) compared histochemical studies to have a role to transit through other regions of A common view at the turn of the in the pathology underlying slow the gastrointestinal tract. As century was that an elongated colon transit constipation in the human intraluminal contents move down (called dolichocolon) was a common large bowel (Cortesini et al. 1995). the large bowel, water and cause of constipation. Although, this Our laboratory has recently electrolytes are absorbed causing concept has been recently discovered a powerful intrinsic the contents to become more challenged (Muller-Lissner et al. neural reflex that likely underlies viscous leading to stool formation. 2005) it still persists in the literature: colonic storage since it is activated This is dramatically illustrated in the ‘... the cause of constipation was by colonic elongation that triggers guinea-pig large bowel, where the colonic slow-transit ... which was myenteric interneurons that release proximal colon contains viscous fluid always associated with dolichocolon ’ NO to depress motility (Dickson et al. chyme that is compacted into soft (Ripetti et al. 2006). However, an 2007a, b). fecal pellets at the flexure between excess production of nitric oxide It is well known that there are two electrophysiological classes of myenteric neuron in the enteric nervous system of the large intestine, called originally AH and S type neurons by Hirst et al. (1974). After-hyperpolarizing (AH) neurons are rapidly adapting, multipolar neurons with one or two processes projecting down to the mucosa. They respond to chemical stimulation of the mucosa and smooth muscle tension (Furness et al. 1998; Smith, 1996; Spencer & Smith, 2004; Smith et al. 2005). In contrast, S (for synaptic) neurons are slowly adapting and receive fast excitatory postsynaptic potentials. They are uniaxonal excitatory and inhibitory motor neurons and ascending and descending interneurons (Lomax & Furness, Figure 1. Effect of circumferential and longitudinal stretch. A, Intracellular 2000; Smith, 1996; Smith et al. 1992; microelectrodes were used to record from the CM at either end of a circumferential Spencer & Smith, 2005). Some stretched preparation (20mm long) of distal colon. Circumferential stretch activated ascending and descending ongoing peristaltic reflex activity consisting of oral excitatory junction potentials interneurons in the distal colon are (EJPs) that were coordinated with anal inhibitory junction potentials (IJPs) in the stretch sensitive in that they detect circular muscle (CM). B, Ongoing peristaltic reflex activity evoked by circumferential stretch was almost abolished by the addition of 60 % longitudinal stretch. circular muscle (CM) length rather C, N omega-nitro-L-arginine (100 µM) added to the middle chamber (7 mm wide) than muscle tension (Smith et al. between the two recording sites restored all ongoing and evoked activity. 2005; Spencer & Smith, 2004). In

Physiology News | No. 69| Winter 2007 | www.physoc.org 34 PN FEATURES circumferentially stretched preparations of distal colon (~20mm long) these interneurons can generate ongoing peristaltic reflex activity even when AH neurons are silent (Spencer & Smith, 2004). This neural activity consists of excitatory junction potentials (EJPs) in the CM at the oral end that are phase locked in both time and amplitude with inhibitory junction potentials (IJPs) at the anal end of the preparation (Fig. 1A; Spencer & Smith, 2004). The only Figure 2. Myenteric circuitry activated by radial stretch and by colonic elongation. way this can occur is if the ascending In preparations where muscle tension has been eliminated by the presence of and descending mechanosensory nifedipine (1 µM; an L-type Ca2+ channel antagonist) circumferential stretch activates interneurons mediating this activity ascending and descending mechanosensory interneurons. These interneurons appear are synapsing with one another to to synapse with one another, thus forming reverberating circuits that coordinate form a reverberating circuit (Fig. 2; ongoing activity between ascending and descending nervous pathways. The Smith et al. 2005; Spencer et al. ascending interneurons activate excitatory motor neurons to the CM. The descending 2006). interneurons activate inhibitory motor neurons to both the CM. This leads to a coordinated oral EJP and an anal IJP in CM at the same time. Orally applied longitudinal stretch (colonic elongation) activates NOS +ve descending interneurons Immunohistochemical coding that release nitric oxide to inhibit action potential firing in mechanosensitive studies of myenteric neurons in the ascending and descending interneurons activated by circumferential stretch. This guinea-pig distal colon have revealed leads to a depression of activity in intrinsic peristaltic nerve circuits. 3 chemically distinct classes of ascending interneurons and 4 classes potential in the muscle, but instead stretch were most likely descending of descending interneurons (Lomax suppressed the ongoing oral EJPs and NOS +ve interneurons, since the & Furness, 2000). We were therefore anal IJPs in the CM in a graded other interneurons contained mainly curious as to whether more of these manner (Fig.1B; Dickson et al. 2007a, ACh and potential peptidergic chemically distinct interneurons in b). We referred to this reflex, which neurotransmitters that are mainly the colon might be mechanosensory. was quite different from that excitatory to other myenteric described by Hukuhara et al. (1960), neurons. Over 40 years ago Hukuhara et al. as an intrinsic occult (hidden or (1960) described a reflex activated obscure) reflex since it suppresses, Calcium imaging followed by by longitudinal stretch. They found rather than evokes, activity in the immunohistochemistry of myenteric that stretching the canine small muscle. Furthermore, this neurons in preparations that had intestine in the longitudinal axis with suppression of activity by been stretched in both axes to inhibit a hemostat produced an active and longitudinal stretch occurred even neurons in peristaltic nerve pathways transient relaxation of the CM that when the longitudinal muscle had revealed ongoing activity in a class of inhibited ongoing rhythmic been removed suggesting that the neurons that were anally projecting contractions, which they referred to sensory processes of the neurons NOS +ve neurons (Dickson et al. as the ‘muscular intrinsic inhibitory mediating this reflex were in the 2007a). Since we had also blocked reflex’. They also found that myenteric plexus or CM (Dickson et synaptic transmission in these removing the longitudinal muscle al. 2007a; Spencer et al. 2006). We preparations with a variety of drugs without apparently disrupting the were surprised to find that blocking we reasoned that these must be myenteric plexus abolished this NO synthesis between the oral and mechanosensitive interneurons reflex, suggesting that the sensory anal recording sites completely responding to colonic elongation, elements mediating this reflex were restored the amplitude and rather than inhibitory motor in the longitudinal muscle (LM) layer. coordination of oral EJPs and anal IJPs neurons. Intracellular microelectrode in the CM, despite the maintained studies revealed that NO mediated Given this result, we were interested longitudinal stretch (Fig. 1C). This inhibitory postsynaptic potentials in determining the effects of suggested that there were specific (IPSPs) could be evoked in longitudinal stretch on the ongoing mechanosensory neurons that mechanosensory interneurons. The peristaltic reflex activity generated responded to longitudinal stretch by IPSPs decreased action potential by radial stretch of the guinea-pig releasing NO to inhibit myenteric firing in these interneurons and thus distal colon (Spencer et al. 2002, neurons in peristaltic reflex pathways prevented them from activating 2006). Much to our surprise we (Fig. 2). From the chemical coding excitatory and inhibitory motor found that the addition of studies described above (Lomax & neurons to the muscle. Later studies longitudinal stretch did not produce Furness, 2000), we reasoned that the confirmed that this occult reflex was a relaxation or an inhibitory junction neurons responding to longitudinal polarized since oral, but not anal,

Physiology News | No. 69 | Winter 2007 | www.physoc.org FEATURES PN 35 longitudinal stretch inhibited suppress activity in mechano­ Dickson E, Spencer NJ, Hennig GW, Bayguinov junction potential activity and pellet sensitive interneurons involved in O, Ren J, Heredia D & Smith TK (2007a). An intrinsic occult reflex underlies propulsion (Dickson et al. 2007a, b). peristalsis. Clinically, the intrinsic accommodation and slow transit in the distal occult reflex provides a negative large bowel. Gastroenterology 132, 1912-24. When the guinea-pig distal colon is feedback system that would be removed from the animal it is expected to exacerbate the Dickson E, Ren, Hennig GW, Spencer NJ & Smith TK (2007b). A polarized intrinsic occult normally full of fecal pellets. Under inhibition of motility associated with reflex underlies accommodation and slow these circumstances fecal pellet constipation in an impacted colon. It transit in the large bowel. Gastroenterology A­ evacuation is slow and sporadic remains to be seen whether any 247, S1688. taking ~30 mins to empty all pellets more myenteric interneurons in the compared to approximately a minute colon are also mechanosensory. Furness JB, Kunze WA, Bertrand PP, Clerc N & Bornstein JC (1998). Intrinsic primary afferent for propulsion of a single pellet down neurons of the intestine. Prog Neurobiol 54, an empty segment of distal colon Acknowledgements 1-18. (D’Antona et al. 2001). Interestingly, This study was funded by grants we found that when the isolated Hirst GDS, Holman ME & Spence I (1974). Two from the National Institute of types of neurons in the myenteric plexus of colon is full of pellets it is elongated Diabetes and Digestive and Kidney duodenum in the guinea-pig. J Physiol 236, by about 40% compared to its length Diseases: RO1 DK45713 (TKS). 303–326. following the expulsion of pellets (Smith et al. our unpublished Hukuhara T, Nakayama S & Nanba R (1960). Terence K Smith, Eamonn Locality of receptors concerned with the observations). Therefore, it would intestino-intestinal muscular intrinsic reflexes seem highly plausible to assume J Dickson, Grant W Hennig Jap J Physiol 10, 414-418. that the elongation of the colon Peter O Bayguinov, Nick produced by the pellets activates Lomax AE & Furness JB (2000). Neurochemical J Spencer classification of enteric neurons in the guinea­ the occult reflex that slows pellet pig distal colon. Cell Tissue Res 302, 59-72. propulsion and promotes storage. Department of Physiology & Cell Biology, University of Nevada School Muller-Lissner SA, Kamm MA, Scarpignato C & Our studies have revealed that, in of Medicine, Reno, Nevada, USA Wald A (2005). Myths and misconceptions about chronic constipation. Am J Gastroenterol. addition to AH sensory neurons, 100, 232-242. distinct interneurons in the large References bowel are mechanosensory and Cortesini C, Cianchi F, Infantino A & Lise M Ripetti V, Caputo D, Greco S, Alloni R & respond to either circumferential (1995). Nitric oxide synthase and VIP Coppola R (2006). Is total colectomy the right distribution in enteric nervous system in choice in intractable slow-transit stretch or longitudinal stretch. We idiopathic chronic constipation. Dig Dis Sci 40, constipation? Surgery 140 , 435-440. have described an intrinsic occult 2450-2455. reflex that is activated by colonic Smith TK (1996). An electrophysiological elongation. Colonic elongation D 'Antona G, Hennig GW, Costa M, Humphreys identification of intrinsic sensory neurons that CM & Brookes SJ (2001). Analysis of motor are excited by 5-HT applied to the mucosa in appears to inhibit colonic motility by patterns in the isolated guinea-pig large the guinea-pig proximal colon. J Physiol 495, activating NOS +ve descending intestine by spatio-temporal maps. 102P. interneurons that release NO to Neurogastro Motil 13, 483-492. Smith TK, Bornstein JC & Furness JB (1992). Convergence of reflex pathways excited by distension and mechanical stimulation of the Physiology in Galicia mucosa onto the same myenteric neurons of the guinea-pig small intestine. J Neurosci 12, The International Workshop on 1502–1510. Molecular physiology of membrane transport and cell excitability was a Smith TK, Hennig GW & Spencer NJ (2005). wonderful opportunity not only to Mechanosensory transduction in the enteric listen to presentations by some of the nervous system. Physiology News 58, 23–25. leading researchers in the field (including two Nobel Laureates), but Spencer NJ, Hennig GW & Smith TK (2002). A also to catch a glimpse of Ukrainian rhythmic motor pattern activated by culture and history. The workshop was circumferential stretch in guinea-pig distal participants from the Precarpathian colon. J Physiol 545, 629–648. held in the beautiful village of National University for their enormous Yaremche, nestled in the Carpathian help with directions, translation, tour Spencer NJ & Smith TK (2004). Mechano­ Mountains outside Ivano Frankovsk. guiding and the wonderful cultural sensory S-neurons rather than AH neurons performance, the organizers for overall appear to generate a rhythmic motor pattern The lectures and student coordination and The Physiological in guinea-pig distal colon. J Physiol 558 , presentations were stimulating and Society for funding these valuable 577–596. thought-provoking. The meeting as a learning opportunities. whole was a great combination of Spencer NJ, Dickson EJ, Hennig GW & Smith TK scientific discussion/presentations and Brian Hagen (2006) Sensory elements within the circular muscle are essential for mechanotransduction social interaction. I would especially University of Maryland Biotechnology of ongoing peristaltic reflex activity in guinea­ like to thank the professors and Institute, Baltimore, MD, USA pig distal colon. J Physiol 576, 519-531.

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An integrative approach to control of oxidative phosphorylation during exercise

At the onset of exercise there is an instantaneous increase in energy (i.e. ATP) utilization within the active muscle. This increased ATP demand is accompanied by increases in both substrate-level (i.e. anaerobic) and oxidative (i.e. aerobic) phosphory­ lations, such that muscle ATP content remains relatively constant regardless of the exercise intensity or duration. Muscle O2 consumption, a reflection of mitochondrial oxidative ATP production, can be estimated by pulmonary O2 uptake. During the transition to exercise, pulmonary O2 uptake, and muscle O2 consumption, increase exponentially towards a new level (see Fig. 1, open circles).

As this increase is not 'instantan­ Figure 1. Typical adaptation of oxidative phosphorylation as measured at the lung eous', the deficit in meeting ATP during the transition to exercise (open circles) and the same response measured requirements by oxidative following heavy-intensity 'warm-up' (closed circles). Mean response of 15 subjects metabolism must be met by non­ take from (Gurd et al. 2005; Gurd et al. 2006). oxidative (substrate-level) ATP to moderate-intensity exercise (i.e. single substrate was reviewed by synthesis. Thus, a consequence of an intensity domain associated with Wilson (1994). As cellular PO2 this delay is a metabolic disturbance no, or only a transient, accumulation decreases below approximately 30 within the myocyte which includes a of lactate-) was faster when preceded torr, a given rate of mitochondrial breakdown of creatine phosphate by a bout of heavy-intensity, warm­ respiration can only be sustained by (PCr) and glycogen, and an up exercise (see Fig. 1, closed an increase in [NADH] (or accumulation of creatine (Cr), ADP, + - + circles). Therefore, using this model [NADH]/[NAD ]) or an increase in lactate , protons (H ) and inorganic of prior heavy-intensity exercise, we [ADP] (or decrease in [ATP]/[ADP]), phosphate (Pi). Together these are attempting to understand the or both. We suggest that it is this changes can contribute to increased limitations to the activation of ‘interaction’ between substrate perception of effort and early muscle O2 consumption and concentrations that both limits fatigue. Therefore, faster activation oxidative phosphorylation during the kinetics at the onset of exercise, and of muscle O2 consumption and transition to exercise. is responsible for the speeding of oxidative phosphorylation is pulmonary VO kinetics (and muscle expected to reduce cellular Production of ATP by oxidative 2 O2 consumption) that is observed disturbances, thereby increasing phosphorylation requires the following a prior bout of heavy­ exercise tolerance and performance. presence of O2, reducing equivalents intensity, warm-up exercise. (NADH and FADH2 (NADH for Control or limitations to the rate of simplicity)), ADP and Pi (Fig. 2). During the transition to exercise, any increase of muscle O2 consumption While ADP availability, a substrate that is not present in have been linked to; (i) activation of consequence of an increase in ATP saturating concentrations can limit enzymes and provision of substrate hydrolysis, likely plays a major role in oxidative phosphorylation. (i.e. acetyl CoA and reducing activating mitochondrial oxidative Experimental data obtained from equivalents) to the mitochondrial phosphorylation, the availability of exercising humans demonstrates tricarboxylic acid (TCA) cycle and other substrates (O2 and NADH) may that intracellular PO2 is approxi­ electron transport chain (ETC); and limit the rate of activation of mately 30-40 torr at rest and (ii) adjustments of muscle blood flow oxidative phosphorylation at a given decreases to less than 10 torr at and O2 delivery during the transition ADP concentration ([ADP]) or ratio relatively light-intensities of exercise to exercise. In two recent [ATP]/[ADP][Pi]. A role for the (Richardson et al. 1995) – i.e. below publications (Gurd et al. 2005, 2006) interaction between the 30 torr where oxidative phosphoryla­ we demonstrated that the kinetics of concentrations of O2, NADH and ADP tion begins to display a dependency pulmonary VO2 (and muscle O2 in regulating mitochondrial oxidative on intracellular PO2. Technical consumption) during the transition phosphorylation rather than by a limitations have prevented an

Physiology News | No. 69 | Winter 2007 | www.physoc.org FEATURES PN 37

Attempts to increase only a single concentration) and iii) greater substrate prior to the onset of mitochondrial PDH activity which exercise experimentally have contributes to a greater muscle produced varying findings. Studies acetyl CoA and NADH content

attempting to increase [O2] have (determined by muscle biopsy of the utilized pump perfusion and quadriceps muscle group) (Gurd et hyperoxia in animal models, and al. 2005; Gurd et al. 2006). The elevated central (cardiac output) or discrepancy between this finding

peripheral blood flow and O2 delivery and that of other studies where only in humans, most of which failed to a single substrate was augmented

speed the rate of pulmonary VO2 (or (i.e. O2 or NADH, see above) is that muscle O2 consumption) (see following heavy-intensity exercise,

Tschakovsky & Hughson, 1999 for both O2 and NADH availability are review). Similarly, attempts to elevated prior to the onset of increase [NADH] during the exercise and thus are immediately transition to exercise by prior available to the mitochondrial ETC. activation of the mitochondrial Therefore, the faster rate of pyruvate dehydrogenase (PDH) activation of oxidative complex and increased flux of phosphorylation seen after heavy­ carbohydrate-derived substrate into intensity exercise is a consequence of the TCA cycle (by means of removing any limitation imposed by dichloroacetate administration) also either muscle perfusion and O2 have yielded mixed results (see delivery, or enzyme activation and Grassi, 2005 for review). However, as NADH availability, or both. Figure 2. Schematic of oxidative discussed earlier it appears that phosphorylation and the delivery of neither O2 nor NADH are present in An interesting observation from our oxidative substrate to the electron saturating concentrations and thus recent publications was that the transport chain (ETC) and mitochondrial should exert control over the rate of relative speeding of pulmonary VO ATPase from the myofilament ATPase oxidative phosphorylation. 2 (ADP), muscle perfusion (O2) and kinetics that was seen in our subjects carbohydrate metabolism (NADH via We recently demonstrated: i) faster was not consistent, but was glycolysis, pyruvate dehydrogenase pulmonary VO2 (i.e. oxidative dependent on their initial rate of (PDH) and the tricarboxylic acid (TCA) phosphorylation) kinetics following adaptation (Fig. 3) – i.e. the cycle). heavy-intensity, warm-up exercise in speeding of kinetics was less in association with ii) greater muscle those subjects who presented with perfusion (determined by near­ faster VO2 kinetics in the ‘no warm­ accurate estimation of infrared spectroscopy (NIRS)-derived up’ condition. Many studies intramitochondrial [NADH] at rest or increase in total and oxygenated examining control of oxidative during exercise. However, there is haemoglobin-myoglobin phosphorylation have used healthy, evidence that an increase in muscle acetyl group availability via elevated flux through PDH, and subsequently, muscle NADH content can result in a faster activation of oxidative phosphorylation (Howlett et al.

1999). Unlike [O2] and [NADH] which, early in the exercise transition, depend on the adaptation of blood flow and carbohydrate metabolism, respectively, [ADP] begins to increase as soon as muscle contraction is initiated and continues until a new steady-state of ATP synthesis is established. Thus, [ADP] exerts control over the rate of oxidative phosphorylation Figure 3. The relationship between τMod1 and the change in τ (∆τ) between Mod1 independent of the concentration of (without 'warm-up') and Mod2 (with 'warm-up') for the activation of oxidative 2 O2 or NADH and can therefore be phosphorylation during the transition to exercise (y-intercept = -6.4; slope = 0.47; r = said to be the driving substrate for 0.71; p < 0.05). Data are taken from (Gurd et al., 2005) (closed circles) and (Gurd et oxidative phosphorylation. al. 2006) (open circles).

Physiology News | No. 69 | Winter 2007 | www.physoc.org 38 PN FEATURES physically fit, young adults or animal disturbances linked to fatigue and models using highly capillarized, exercise intolerance. oxidative muscle preparations. In Forthcoming Symposia these instances the adaptation of Brendon J Gurd1, George J F Store -operated calcium channels: pulmonary VO2 kinetics and muscle 3 Heigenhauser ,Donald H mechanism and function O2 consumption is relatively rapid 1 Friday 1 February 2008 (time constant (τ) ~ 20 s). Thus, any Paterson ,John M 1,2 1200–1700 speeding in the adaptation of Kowalchuk At Biophysical Society Annual Meeting, oxidative phosphorylation resulting 1 Canadian Centre for Activity and Long Beach Convention Center, Long from an intervention in healthy, Aging, School of Kinesiology, Faculty Beach, CA, USA physically fit, young humans or in of Health Sciences, Department of (http://www.biophysics.org) oxidative animal muscle preparations Physiology and Pharmacology is likely to be small and difficult to The role of GABA and glutamate on 2Schulich School of Medicine and detect. The situation is likely to be adult neurogenesis Dentistry, The University of Western exacerbated in situations where only Wednesday 9 April 2008 Ontario, London, Ontario, Canada a single substrate is elevated, such as 0800–1000 in the previously mentioned studies 3Department of Medicine, McMaster At Experimental Biology 2008, San Diego where either [O2] or [NADH] was University, Hamilton, Ontario, Convention Center, San Diego, CA, USA increased alone. Canada L2S 3A1. (http://www.eb2008.org)

Interestingly, in cases where References Retinal ganglion cells in model organisms: development, function and elevating one or more substrate(s) Grassi B (2005). Delayed metabolic activation was successful in speeding the of oxidative phosphorylation in skeletal disease activation of oxidative muscle at exercise onset. Med Sci Sports Exerc Saturday 26 April 2008 phosphorylation, full activation was 37, 1567–1573. 1245–1635 still not instantaneous. This period At ARVO 2008, Broward County Gurd B, Peters SJ, Heigenhauser GJ, LeBlanc PJ, may represent the time required for Convention Center, Fort Lauderdale, FL, Doherty TJ, Paterson DH & Kowalchuk JM USA ADP to increase to appropriate levels (2006). Prior heavy exercise elevates pyruvate ( http://www.arvo.org) to drive oxidative phosphorylation. dehydrogenase activity and speeds O2 uptake Consistent with this idea is the kinetics during subsequent moderate­ finding that rapid increases in [ADP] intensity exercise in healthy young adults. J For further information on The Journal of Physiol 577, 985–996. Physiology symposia, including alone (either by iodoacetamide­ programmes, please visit induced inhibition of the creatine Gurd BJ, Scheuermann BW, Paterson DH & http://jp.physoc.org/symposia. kinase (CK) reaction or by using CK­ Kowalchuk JM (2005). Prior heavy-intensity knockout mice) result in a exercise speeds VO2 kinetics during moderate­ Non-Society scientific meetings significantly faster activation of intensity exercise in young adults. J Appl Physiol 98, 1371–1378. oxidative phosphorylation during the What do we want to see in brain imaging? 3–4 December 2007 transition to exercise (for an example Howlett RA, Heigenhauser GJF, Hultman E, Royal Institute of British Architects, London, see Kindig et al. 2005). Hollidge-Horvet & Spriet LL (1999). Effects of UK (http://www.nyas.org/IMGconf). dichloroacetate infusion on human skeletal muscle metabolism at the onset of exercise. BPS Winter Meeting The adaptation of oxidative Am J Physiol 277, E18–25. 18–20 December 2007 phosphorylation during the Hilton Metropole, Brighton, UK transition to exercise appears to be Kindig CA, Howlett RA, Stary CM, Walsh B & (http://www.bps.ac.uk). Hogan MC (2005). Effects of acute creatine dependant on the provision of ADP Pacific symposium on biocomputing with the availability of O and NADH kinase inhibition on metabolism and tension 2 development in isolated single myocytes. J 4–8 January 2008 acting as modulators. Our own data Appl Physiol 98, 541–549. Fairmont Orchid, Hawaii, USA show that if, before the start of (http://psb.stanford.edu). Richardson RS, Noyszewski EA, Kendrick KF, exercise, muscle perfusion and O2 International symposium on resistance Leigh JS & Wagner PD (1995). Myoglobin arteries delivery and muscle substrate desaturation during exercise. Evidence of 17–21 February 2008 (pyruvate) and enzyme (PDH) limited O2 Transport. J Clin Invest 96, Hamilton Island, Great Barrier Reef, activities are elevated, the rate of 1916–1926. Queensland, Australia activation of mitochondrial oxidative (http://medicalsciences.med.unsw.edu.au). Tschakovsky ME & Hughson RL (1999). phosphorylation and O2 Interaction of factors determining oxygen We regularly receive information about consumption (as determined by uptake at the onset of exercise. J Appl Physiol scientific and other meetings from external 86, 1101–1113. pulmonary VO2 ) is faster compared organisations and post those that we think to a control condition. As a might be of interest to our Members on our consequence substrate-level Wilson DF (1994). Factors affecting the rate web site. For the current list of forthcoming and energetics of mitochondrial oxidative events please visit: phosphorylations are minimized, phosphorylation. Med Sci Sports Exerc 26, which should reduce metabolic 37–43. http://www.physoc.org/meetings

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Contribution of myoglobin facilitated O2 diffusion in respiring tissue

Sometimes scientists stumble hypothesis? Solution experiments innocently into a research question confirm that the NMR determined and then discover that the results do diffusion coefficients of 11.6 x 10-7 not match the accepted views. Hand cm2/s (Mb) and 7.53 x 10-7 cm2/s (Hb) wringing usually rues the naivety, agree closely with literature reported while peers rush to explain away the values. In respiring rat myocardium, new observations with methodology Mb diffusion drops by 37% to 4.24 x doubts. But if the observations hold, -7 2 10 cm /s. The cellular DMb matches a new idea can rise. the value predicted by the NMR rotational diffusion analysis (Wang et Figure 1. Ping Chang Lin (left), Thomas For many, the function of myoglobin al. 1997). (Mb) poses no question. All Jue and Ulrike Kreutzer standing in front of a Mb diffusion poster at the University biochemistry textbooks assert that Given the cellular DMb, the cellular Mb of California Davis laboratory. Mb stores or transports oxygen. The concentration, the Mb P50 (PO2 that half saturates Mb), and K0 (the view seems reasonable, given its now detected the distinct γ CH3 Val structural features, its O2 binding, and E11 and proximal histidyl NδH signals diffusion of free O2 in the cell), the its homology with hemoglobin (Hb). of Mb in myocardium and skeletal data analysis can assess the relative Indeed, Kendrew and Perutz muscle, an opportunity has emerged contribution of the O2 flux from Mb (FO Mb) vs. from free O (FO O2), as established a field of protein to determine cellular PO2 and to apply 2 2 2 crystallography by describing the pulsed-field gradient techniques to defined by an equipoise diffusion PO2, structure of these heme proteins. map endogenous Mb translational the PO2 in which Mb and free O2 Monod, Wyman, and Changeux diffusion (Kreutzer et al. 1992; Stejskal contribute equally to the cellular O2 explained O2 binding to Hb with a two & Tanner, 1965). flux. For the rat heart, the equipoise state model paradigm. Given the PO2 stands around 1.8 mm Hg. Below 1 tomes of experimental data, Mb or Hb In the basal state, H NMR has not a PO2 of 1.8 mm Hg, the Mb structure or function should stand on detected any deoxy Mb proximal dependent contribution to the O2 flux a solid conceptual framework. histidyl NδH signal in perfused or in dominates. Because the NMR situ myocardium. In contrast, the Mb observation indicates that the basal But Wyman actually puzzled over Mb facilitated diffusion hypothesis state in situ myocardium operates function in the cell. Its concentration envisions a partially saturated Mb in with a PO2 above 10 mm Hg, Mb in terrestrial mammals seemed too blood perfused tissue. Even as work cannot play a significant role in low to serve as an adequate oxygen doubles, the in situ myocardium facilitating O2 transport under normal store. He proved mathematically a shows no signs of Mb desaturation physiological conditions in the theory proposed by Wittenberg. (Kreutzer et al. 2001; Zhang et al. myocardium. Namely, Mb can compete effectively 1999). with free O2 in delivering oxygen to The concentration of Mb alters the mitochondria. In essence the high What about the other assumption in significantly the equipoise PO2. In

O2 carrying capacity of Mb overcomes the Mb facilitated diffusion terrestrial mammalian muscle, the Mb the low solubility of free O2. Two assumptions underpin the hypothesis: cellular O2 in blood perfused tissue only partially saturates Mb, and cellular Mb must have sufficient mobility to compete with free O2 diffusion. At high O2 levels, as characterized by a fully saturated Mb, the diffusion of free O2 will transport more efficiently than Mb. If Mb diffuses too slowly, it cannot compete effectively with free O2 diffusion.

The Mb facilitated O2 diffusion hypothesis, however, has languished 1 for definitive experimental verification Figure 2. H NMR diffusion-weighted spectra of MbO2 from perfused rat heart under for over 40 years. Nevertheless, these KCl arrest at 22 oC: a modified PG-STE sequence detects the peak intensity change in ideas about Mb function form the the MbO2 γ CH3 Val E11 signal at -2.8 ppm as a function of gradient field strength in cornerstone of current respiratory the Y direction: A, 84.2 gauss/cm; B,74.8 gauss/cm; C, 56.1 gauss/cm; D, 37.4 control models. Because 1H NMR has gauss/cm, and (E) 4.7 gauss/cm.

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governing protein structure function relationship. Acknowledgements We gratefully acknowledge funding support from NIH GM 58688 (TJ), Philip Morris 005510 (TJ), and American Heart Association Western States Affiliate 0265319Y (UK) and the invaluable technical assistance of Jeff Walton and Jeff de Ropp.

Ping Chang Lin Ulrike Kreutzer Thomas Jue Biochemistry and Molecular Medicine, University of California Figure 3. Plot of free O2 flux vs. Mb facilitated O2 diffusion as a function of PO2 at o Davis, Davis, CA, USA 22 C: the free O2 flux increases linearly with PO2. Two lines depict the rate of -5 -1 ­ change given a cellular free O2 diffusion constant of K0 = 4.28x10 ml O2 cm min 1 -1 -5 -1 -1 -1 References atm and K0 = 2.52x10 ml O2 cm min atm . The two non-linear curves show the Chung Y, Mole PA, Sailasuta N, Tran TK, Hurd R O2 flux contribution from Mb facilitated diffusion increases as the cellular Mb concentration rises from 0.19 mM to 0.42 mM. With a P50 of 2.3 (---) and 1.5 mm & Jue T (2005). Control of respiration and bioenergetics during muscle contraction. Am J Hg (—). With a P50 of 1.5 mm Hg, the equipoise PO2 values are 1.77 (0.19 mM Mb, Physiol Cell Physiol 288, C730–C738. -5 -1 -1 -1 -5 ­ K0=2.52x10 ml O2 cm min atm ) and 5.72 (0.42 mM Mb, K0=2.52x10 ml O2 cm 1 -1 -1 min atm ). With a P50 of 2.3 mm Hg, the equipoise PO2 falls to 0.97 and 4.92 mm Flogel U, Merx MW, Godecke A, Decking UKM Hg, respectively. & Schrader J (2001). Myoglobin: a scavenger of bioactive NO. Proc Natl Acad Sci 98, concentration ranges from 0.19 mM cellular environment. In solution, Mb 735–740. in heart muscle to 0.42 mM in soleus diffuses isotropically; in the cell, Mb muscle. Soleus muscle has then a can exhibit anisotropic diffusion, since Kreutzer U & Jue T (2006). Investigation of bioactive NO-scavenging role of myoglobin in higher equipoise PO2 than the longitudinal dimension exceeds myocardium. Eur J Physiol 452, 36–42. myo-cardium. In fact, marine the radial dimension by a factor of 10. mammalian muscle with Mb However, the translational diffusion Kreutzer U & Jue T (2004). The role of concentration up to 25-70 g/kg tissue measurements show no orientation myoglobin as a scavenger of cellular NO in myocardium. Am J Physiol 286, H985–H991. (approximately 1.4-4 mM) would have preference. Consequently, within a an equipoise PO2 of 12-38 mm Hg. mean squared displacement of 3.8 Kreutzer U, Mekhamer Y, Chung Y & Jue T With marine mammals, Mb µm, as determined from the (2001). Oxygen supply and oxidative phosphorylation limitation in rat myocardium dependent O2 diffusion dominates measured DMb, Mb encounters no in situ. Am J Physiol Heart Circ Physiol 280, even under resting conditions. diffusion restrictions and experiences H2030–H2037. no cellular crowding, which could What then is the function of Mb? potentially modulate chemical Kreutzer U, Wang DS & Jue T (1992). Recent studies have claimed an NO reactivity. The cell contains many local Observing the 1H NMR signal of the myoglobin scavenging role, even though other fluid domains. Val-E11 in myocardium: An index of cellular experiments have not detected the oxygenation. Proc Natl Acad Sci 89, 4731–4733. required presence of oxidized Mb In summary, pulsed-field gradient (Flogel et al. 2001; Kreutzer & Jue, NMR methods have determined the Mole PA, Chung Y, Tran TK, Sailasuta N, Hurd R 2006; Kreutzer & Jue, 2004). Another endogenous Mb diffusion in respiring & Jue T (1999). Myoglobin desaturation with perspective emerges from skeletal rat myocardium. In myocardium, Mb exercise intensity in human gastrocnemius muscle experiments. At the start of cannot play a significant role to muscle. Am J Physiol 277, R173–R180. muscle contraction, Mb desaturates facilitate O2 diffusion. In skeletal Stejskal EO & Tanner JE (1965). Spin diffusion within 30s to reach a steady state muscle, it may play a role at the measurements: spin echoes in the presence of deoxygenation state, even though the initiation of contraction. In marine a time-dependent field gradient. J Chem Phys 42, 288–292. cell has abundant O2 to drive oxidative mammalian muscle, Mb contribution phosphorylation (Mole et al. 1999; to O2 flux predominates in the cell, Wang D, Kreutzer U, Chung Y & Jue T (1997). Chung et al. 2005). MbO2 appears to which contains many local fluid Myoglobin and hemoglobin rotational respond to a transient rather than a domains. diffusion in the cell. Biophys J 73, 2764–2770. steady state change in energy demand. What then is the function of Mb? Zhang J, Murakami Y, Zhang Y, Cho Y, Ye Y, Despite textbook reassurances, that Gong G, Bache R, Ugurbil K & From AHL (1999). Oxygen delivery does not limit cardiac The Mb translational diffusion simple question still challenges performance during high work states. Am J coefficient also yields insight into the physiology and the search for the laws Physiol 276, H50–H57.

Physiology News | No. 69| Winter 2007 | www.physoc.org EDUCATION PN 41

Teaching ethics to students from the suite we have developed. physiology students We build on these sessions at level 2, There are many sensitive and when students have acquired some contentious areas within physiology subject-specific knowledge and are such as the ‘use of animals in research ’ now more ethically aware, again or ‘genetic modification’, each with covering generic issues which may their own ethical issues or dilemmas. arise in their degree programme or The practice of scientific research itself future research careers (e.g. ‘scientific also has ethical implications, for integrity’) and discipline-specific example ‘scientific integrity’, ‘data issues (e.g. ‘use of human subjects and the principles of informed consent’). fabrication’ and ‘ownership of data’. Dave Lewis - ‘our aim is not to produce These latter sessions are an We should be making our students philosophers but to train our students so aware of these issues and be providing that they have the ability to think opportunity not only to address the training for them in ethics and ethical through ethical issues’. ethical issues but also to provide thinking. Indeed, the QAA biosciences knowledge of the relevant UK law; this 1 need to incorporate both ethics and benchmark statement states that ‘ outside the box’; to learn how to law is best highlighted by sessions on ‘ students should be confronted by develop and deliver rational/logical the ‘use of animals in scientific some of the scientific, moral and arguments including those with which research’. The majority of ethical questions raised by their study they don't necessarily agree; all of undergraduate students in the life discipline’; the provision of ethics which are key transferable skills that sciences do not use live animals in their training for postgraduate students is are highly sought after by employers. also required by the Research studies; instead they undertake 2 isolated tissue experiments or cadaver Councils . We therefore set out to When undergraduate students enter dissections. When such students are provide a comprehensive and level 1, they have had little or no questioned, the majority have not progressive training in ethics and training in critical thinking; they also thought about where the tissue has ethical thinking, not only to physiology have scant discipline-specific come from or the ethical implications students, but to all undergraduate and knowledge. To cater for this we have of its use; the few that have, confess to postgraduate students within the developed sessions such as a ‘life blanking out such considerations. Faculty of Biological Sciences at the skills’ seminar which considers the They also have little knowledge of University of Leeds. Like most life ethical issues surrounding alcohol relevant UK law and have serious scientists we have little or no training promotions and cheap credit. misconceptions or misunderstandings in philosophy. However, the University Designed to be utilised either in about the use of animals in research, was awarded a HEFCE-funded Centre freshers’ week or the first 2 weeks of their opinions influenced by the of Excellence in Teaching and Learning term when the students are facing popular and/or teen press. Student in ethics, the interdisciplinary Ethics these issues in real life, its purpose is to feedback has shown that, by the end of Applied (IDEA) CETL3. We have get them thinking/discussing a these seminars, this has been therefore been able to work in particular ethical issue without remedied; they now have both the partnership with applied ethicists from becoming bogged down by the knowledge and ethical awareness of the CETL to design, develop and deliver underlying science. Having used this the issues involved to enable them to truly interdisciplinary ethics teaching. session to introduce them to ethical make a more informed decision about thinking, the remaining sessions in the use of animals in research. Our aim is not to produce philosophers level 1 are science-based, covering but to train our students so that they both generic issues which are relevant At levels 1 and 2, these ethics sessions have the ability to think through to all students within the biological are fully integrated within the most ethical issues as they arise, either in the sciences (e.g. ‘roles and appropriate core modules in the remainder of their degree courses or responsibilities of a scientist’ or different degree programmes, for subsequently in their future careers. ‘plagiarism’) and discipline-specific example practical skills, tutorial or As such, ‘ethics’ is probably too issues which students should be able research orientated modules, ensuring narrow a term, a training in critical to address from prior general that all students are provided with a thinking might be a more appropriate knowledge (e.g. ‘drugs in the 3rd training in ethics. Case studies, description as ethics teaching sessions world’ or ‘coaching children’). student notes and comprehensive provide an opportunity for students to Individual programme managers are tutor notes have been developed for thinking critically about a problem (but free to choose the most appropriate each session enabling them to be ethical issues in particular); to think sessions for their particular cohort of delivered by a non-specialist. Our aim 1 The Quality Assurance Agency for Higher Education (2002) is to make these materials available, http://www.qaa.ac.uk/academicinfrastructure/benchmark/honours/biosciences.asp#1 through the IDEA CETL3, to colleagues 2 Research councils skills statement (2001) at other Institutions. http://www.bbsrc.ac.uk/funding/training/skill_train_req.pdf 3 Interdisciplinary Ethics Applied Centre of Excellence in Teaching and Learning (IDEA CETL). By level 3, significant numbers of our http://www.idea.leeds.ac.uk students have developed an interest in

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ethics. To cater for such students, and requested more such sessions. We 1 and 2 and in all of our postgraduate in contrast to earlier levels where believe the success of this teaching is programmes. ethics teaching is provided within due to its delivery as individual individual modules, we have sessions integrated within existing Our focus for the following year is to developed an optional ethics module modules using topical and discipline­ refine this teaching in response to staff for physiology, pharmacology, medical specific case studies. Evidence from and student feedback and also to sciences and neuroscience students other faculties in the University (where develop a Faculty-wide level 3 optional which addresses issues including the CETL is also working) suggests that ethics module which addresses the ‘ research on embryos’ and ‘science students do not engage with case ethical issues arising from the principal and society versus the individual’. We studies they perceive as not relevant to areas of research within the Faculty. are also trialling ethics-based final year them or where, at least at levels 1 and teaching projects in local schools. 2, ethics teaching is delivered as stand­ Dave Lewis Students deliver, as part of the school alone modules. Senior Lecturer, Institute of curriculum, a set of ethics-based Membrane & Systems Biology, teaching sessions on areas of current This development of ethics training Faculty of Biological Sciences, topical interest, evaluating ethical within the faculty is on-going. By the opinions before and after these end of the 2007-2008 academic year, University of Leeds and sessions and also the effectiveness of ethics will be firmly embedded Interdisciplinary Ethics Applied the teaching package itself, writing the throughout most of our under­ Centre of Excellence in Teaching & study up as their final year research graduate degree programmes at levels Learning (IDEA CETL). project. These projects will cater for the increased public interest in ethical issues in science, provide student LETTER TO THE EDITOR training in science communication and Living History promote the public understanding of Professor Hugh Huxley of Brandeis University has pointed out to me that I science in local schools. They are made an error in my recent article (Elliott GF (2007). X-rays, twitching muscles therefore a valuable alternative to wet­ and burning anodes. Physiology News 67, 6-10) in suggesting Dr Max Perutz based laboratory projects and are was responsible for the back-to- back publication of two papers (on X-ray particularly suitable for those students diffraction data from living striated muscle during contraction) from King' s who don’t go on to research careers . College (London) and from Cambridge in Nature in 1965. This development of ethics training is Hugh Huxley sent me a photocopy of a handwritten letter that I had sent to not restricted to our undergraduate him on 7 May of that year attaching a copy of the paper the King’s College programmes; we are also developing group submitted to Nature on 14 April. I had not seen this letter in 40+ years, ethics training courses for all of our and reading it again brought the events back to me with total clarity. As it taught and research postgraduate happened, the letter was my solution to an internal problem among the KCL students. These students come from a authors. Two of the authors, including myself, had thought it discourteous to wide range of backgrounds, nationalities and cultures, resulting in Hugh Huxley that we had not sent him a copy of our paper when we different levels of ethical awareness submitted it to Nature. However, one author had wished to wait until it was and indeed ethical values. Our accepted and had been supported in this view by other senior members of the research suggests that they benefit KCL laboratory; I had found myself in the minority. most from discipline specific training There was to be a muscle research dinner later in May that year. As the date delivered at a Faculty level rather than approached without our hearing from Nature about the paper I felt centrally delivered provision. We have increasingly uncomfortable at the prospect of talking to Hugh Huxley in such therefore developed a series of ethics circumstances, since he had always been very friendly and helpful to me. I seminars for these students, with therefore asserted my rights as first author and sent him a copy; it was this act similar topics to those for that initiated the negotiations that ultimately resulted in the back-to- back undergraduates, but with the content publication in Nature. I had forgotten these details because Jack Lowy carried altered to cater specifically for the out the actual negotiations. Jack subsequently took all the relevant copies and needs of postgraduate students. records with him to Denmark, including our copy of my letter, and I never saw them again. So how has this ethics teaching been received by students? Beforehand, the I am happy to agree with Hugh Huxley that Max Perutz was not involved, as I majority of students were unimpressed had imagined and as I wrote in my article. My comment about Max was about having to attend ethics sessions actually made with affection, since Max, now sadly missed by us all, was one and didn’t see the relevance to their of my scientific heroes and was a true gentleman in the best sense of the studies. Afterwards, their opinions word. Hugh Huxley has pointed out, though, that what I wrote could be seen have changed. Quantitative and as a black mark on Max's memory. I am delighted that I can set the record qualitative feedback has been very straight and remove any implied, though unintended, criticism. good, students enjoyed this teaching, they report that their awareness of Gerald Elliott ethical issues has increased and they Nuffield Laboratory of Ophthalmology, University of Oxford, UK

Physiology News | No. 69 | Winter 2007 | www.physoc.org SOCIETY JOURNALS PN 43

Celebrating publishing 100 years of discovery in physiology 1908–2008 The Paton Lecture The January 2008 issue, 93.1, will contain the Paton Lecture Claude Bernard, the first systems biologist, and the future of physiology, presented by Denis Noble at LifeSciences2007 in Glasgow in July.

Historical perspective series Througout Experimental Physiology’s centenary year a series of invited articles will be published in which experts in the field bring a current Denis Noble (above left) receives the perspective to a historical article Paton Lecture certificate from David Paterson; Sir Edward Sharpey-Schafer Chairman, David Paterson, published in The Quarterly Journal of Experimental Physiology. Contributors (below), founder of the Quarterly Journal welcomed the Editorial Board to of Experimental Physiology. Merton College, Oxford (above) for will include: their September meeting. The Uwe Proske on PBC Matthews (1962). The meeting was well attended by differentiation of two types of fusimotor fibre Editors from the UK, USA and New by their effects on the dynamic response of Zealand, as well as representatives muscle spindle primary endings. Q J Exp Physiol Cogn Med Sci 47, 324-333. from Wiley-Blackwell and The Physiological Society. Plans were Walter St John on Fritz Buchthal (1959). discussed for the journal’s Electromyography of intrinsic laryngeal forthcoming centenary year. muscles. Q J Exp Physiol Cogn Med Sci 44, 149­ 159.

Monthly online publication for James FX Jones on P Alcock, JL Berry & I de 2008 Burgh Daly (1935). The action of drugs on the After 100 years of predominantly pulmonary cirulation. Q J Exp Physiol 25, 369­ 392. quarterly and bi-monthly publication, Experimental Physiology Roger Lemon on ASF Leyton & CS Sherrington will be published monthly online (1917). Observations on the excitable cortex from 2008 to celebrate the success of the chimpanzee, orang-utan and gorilla. Q J Exp Physiol 11, 135-222. of the journal during its centenary news for publishers who are finding year and to reflect increasing interest John Morrison on FJF Barrington (1925). The that duplicate publication is on the in it. Double issues will be printed effect of lesions of the hind- and mid-brain on increase, an observation that has and dispatched bi-monthly. micturition In the cat. Q J Exp Physiol 15, 81­ been borne out recently in the 102. Society’s journals. In the past, Simon Gandevia on Charles Reid (1928). The detection of duplicated material in mechanism of voluntary muscular fatigue. Q J research papers was based largely on Exp Physiol 19, 17-42. serendipity. Typically, the reviewer of Roy Curry on CC Michel, JC Mason, FE Curry, JE a paper recalls that (s)he has read Tooke & PJ Hunter (1974). A development of something recently by the same the Landis technique for measuring the authors or on the same subject, filtration coefficient of individual capillaries in checks up on his/her suspicions and the frog mesentery. Q J Exp Physiol Cogn Med Sci 59, 283-309. finds that indeed parts of a previously published paper are reproduced without acknowledgement in the paper under review. New technology Plagiarism in publishing: makes this kind of duplication all too easy but, copyright issues aside, it checking for duplication should be intuitively obvious that Earlier in this issue (p. 41) Dave Lewis reproducing already published describes how Leeds University are material, even your own, under tackling scientific ethics issues with different publishers’ banners students at all levels. This is welcome without acknowledging the primary

Physiology News | No. 69 | Winter 2007 | www.physoc.org 44 PN SOCIETY JOURNALS source is ethically dubious. Dave particular publisher doesn't have a Lewis points out in his article that problem with plagiarized critical ethical thinking needs to be manuscripts, they should have an taught to trainee scientists. The interest in making sure that their courses offered at Leeds are a own published content is not proactive part of this endeavour. plagiarized or otherwise Active plagiarism detection by illegitimately copied’4. One likely educators and publishers, followed interesting feature of a final system by appropriate sanctions against will be that users can display the offending authors, serves to system logos on their web pages retroactively reinforce the message. which will act as a warning to readers New Journal of and future authors that duplicate Physiology Editors, Recently search engines have started publication will be sought out and is clockwise from above left: Jerrel to play a part in unmasking duplicate not acceptable practice. Yakel, Mark publication. University teachers now Hargreaves and routinely check student essays and The Crosscheck pilot project is Allan Vaag. course work against internet and running for 3 months until early in database sources using duplication 2008. During that time Publication Soderling, he studied the function of detection software such as Office staff will test the software and regulation of ligand-gated ion channels. iThenticate1 and Turnitin2 . These feedback to the project team on the Jerry joined the National Institute of systems work by comparing efficiency and user friendliness of the Environmental Health Sciences as an submitted documents against the system. Based on the rise in cases of investigator in 1993, and is currently a open internet and large databases of duplicate publication involving The Senior Investigator in the Laboratory of published content. Journal editors Society’s journals it is very much in Neurobiology. His laboratory explores have been asking for the same our interests to take part in this the function and regulation of ligand­ facility for their publications offices, initiative and to spread the message gated ion channels, in particular the neuronal nicotinic receptor channels, in but the problem for journals has that plagiarism is regarded by the the hippocampus. been that authors are likely to be scientific publishing community as a duplicating material that is not serious ethical problem which we are Mark Hargreaves is Professor of available to plagiarism detection taking steps to eradicate. Physiology at the University of systems’ search engines which Melbourne, Australia. His research and access only material on the open Carol Huxley teaching interests are in the internet or in their own databases of physiological and metabolic responses appropriate documents. In response New Editors to acute and chronic exercise, with a 3 focus on skeletal muscle carbohydrate to demand, CrossRef , the reference Lothar Blatter, Mark Hargreaves, John metabolism during exercise and the linking service now widely used by Isaac, Stanley Nattel, Mu-Ming Poo, publishers, in partnership with regulation of skeletal muscle GLUT4 Allan Vaag, Anton Wagenmakers and expression. He is also a Consulting iParadigms, the company behind Jerrel Yakel have recently joined the Editor for the Journal of Applied iThenticate, has set up a pilot project, Editorial Board of The Journal of Physiology and an Associate Editor of 4 CrossCheck , to develop a database of Physiology. Exercise and Sport Sciences Reviews. licensed publishers’ content which can be accessed by the iThenticate Jerrel Yakel received his BS from Oregon John Isaac received his BSc in system. Wiley-Blackwell is one of State University, and his PhD from the biochemistry with pharmacology and eight publishers contributing University of California, Los Angeles, his PhD in neuroscience from Howard material to the database for the pilot where he studied ligand-gated ion Wheal’s laboratory at the University of project and The Journal of Physiology channels and serotonin receptors in Southampton, UK. During his is taking part. In the long term, it is cultured hippocampal neurons and cell postdoctoral training in Robert hoped that the vast majority of lines with Meyer Jackson. During a Malenka’s laboratory at the University postdoctoral fellowship with the late publishers will add their content to of California San Francisco he studied Hersch Gerschenfeld at the Ecole the mechanisms of synaptic plasticity in the database, which will be available Normale Superieure (Paris, France), he the hippocampus and barrel cortex. He under specified terms and conditions investigated the regulation of voltage­ started his own laboratory at the to plagiarism detection systems. gated calcium channels by G protein­ University of Bristol, UK, where he CrossRef believes that publishers will coupled receptors. During a second became a full professor in April 2004. In be willing to cooperate in creating postdoctoral stage at the Vollum September 2004 he joined NINDS as an the required database: ‘Even if a Institute with Alan North and Tom investigator and established the Developmental Synaptic Plasticity Unit. 1 http://www.ithenticate.com/static/home.html His group studies molecular and cellular 2 http://turnitin.com/login_page.asp mechanisms of developmental synaptic 3 http://www.crossref.org/webservices.html plasticity in the hippocampus and barrel 4 http://www.crossref.org/crosscheck.html cortex.

Physiology News | No. 69 | Winter 2007 | www.physoc.org MEMORABLE MEMBERS PN 45

Joseph Francis Donegan inexperienced, was invited to excitation, a hot topic at the time, succeed him. These were difficult attracted his attention. This led to 1893–1985 times in Ireland in the aftermath of a the John Mallet Purser Lecture he gruelling world war and civil gave at Trinity College Dublin in Joseph Francis Donegan was a much insurrection at home. It might have 1942 (Donegan, 1942). Such was his loved member of The Society for been better for Donegan to remain in interest that when he retired he set almost 60 years. Born in Gurteen, centres where his investigative up a small laboratory in his own County Sligo in 1893, he read talents would have greater scope. house to continue the work. medicine at University College But his feelings for Ireland and his Galway where he was a brilliant alma mater led him to accept the Donegan maintained an up-to-date student, graduating BSc (1914) and chair. So for a while full time knowledge in most fields of MB, BCh (1916) with first class research was replaced with near full physiology by his avid reading, honours and a love of physiology. time teaching but his investigative constant teaching and attending His insatiable curiosity and ability led curiosity was not quelled. At the July meetings, where he would sit in the one of his teachers, J P Pye, and an 1924 meeting of The Society in front row and put penetrating external examiner, Joseph Barcroft Oxford, with Sir Charles Sherrington questions to the speakers whatever (Cambridge) to guide him towards in the chair, he was elected to the topic. Couched in simple terms an academic career. Because local membership. with a puckish good humour and a research facilities were limited, he sparkling eye, they enlivened the was encouraged to train elsewhere. An opportunity for further research meetings but sometimes came in the summer vacation of discomfited the authors. Various travelling fellowships took 1927 when he visited Otto him first to Cambridge, where he Warburg’s world famous In Galway where he held the chair for worked with Barcroft, Adair and department at the Kaiser Wilhelm over 40 years, he became a legend. Parsons on the relationship between Institute for Biology in He had a liking for fast cars: he blood pH and its O2 and CO2 Berlin–Dahlem. Warburg won a owned a Bugatti that was said to combining power (Parson & Nobel Prize for Medicine and clear the road to the College of Donegan, 1918–19). Then he Physiology as did several others who traffic when the approaching vroom worked with Thomas Milroy in worked there including Otto of its engine was heard. He was a Belfast on the colloid osmotic Meyerhof, Hans Krebs, Fritz Lipmann, highly disciplined man of regular pressure of blood following Severo Ochoa and Hugo Theorell. habits and somewhat obsessive haemorrhage (Milroy & Donegan, The group met for sandwich lunches about punctuality. His classes began 1919). In 1919 he moved to where they discussed their work. and ended precisely on time. His University College London with an Donegan was so taken with the lectures were clear, well discussed 1851 Exhibition Research Fellowship ethos of the group that he arranged and larded with personal opinion. where he worked with Bayliss and to spend a sabbatical year there in With a sharp tongue, he was Starling. Ernest Starling, with his 1928 at his own expense. During outspoken to delinquent students, so interest in the contribution of venous that year he collaborated with Hans was not often provoked. He ran the return to cardiac output, encouraged Krebs in developing a method for practical classes himself and came a study of the nervous regulation of peptide cleavage (Donegan & Krebs, around to quiz each pair of students veins, a little understood topic at the 1929). He considered these times in turn on their work. His remit time. With great technical skill, among the most exciting and included biochemistry and Donegan carried out the pioneer influential in his life in both scientific pharmacology. work (Donegan, 1921) that is still and musical terms. He cited in contemporary reviews of commemorated his time there by As a formidable hill walker he could vein physiology. naming his house in Galway Dahlem. out-walk most of his junior colleagues and contemporaries. He When J P Pye died in 1920 Donegan, When he returned to Galway, the loved music and was very though only 27 and relatively role of intracellular potassium in knowledgeable about it: it was said that his first attachment to Berlin Olympic Special Issue maximal oxygen uptake in elite was timed to coincide with the athletes; Beethoven Centenary celebrations. The January 2008 issue of The • Doping and athletic performance; When in London for meetings he Journal of Physiology will be an • Dietary manipulations that influence could usually be found the night gene expression and performance; Olympics Special Issue, edited by before at concerts in the Royal • Exercise in the heat; Michael Joyner and Bengt Saltin. Festival Hall. Topics to be covered include: • Muscle fatigue; • Master athletes and aging; • What has physiology learned from • Exercise performance: nature vs. When he retired in 1962 aged 70 he athletic performance? nurture. was elected to The Society' s • Physiological determinants of Issue online 1 January 2008 Committee where his wisdom was

Physiology News | No. 69 | Winter 2007 | www.physoc.org 46 PN MEMORABLE MEMBERS/BENEVOLENT FUND widely appreciated. Through him other hand the fun, excitement and References The Society held its first and very discipline of physiology that he Donegan JF & Parsons TR (1918–19). Some successful meeting in Galway in conveyed to generations of students, further observations on blood reaction. J 1965. In 1976, when he was 84, The contemporaries and The Society Physiol 52, 315–327. Society elected him to Honorary should not be gainsaid – it was a Donegan JF (1921). The physiology of veins. J membership, an honour he memorable achievement by a Physiol 55 226–245. appreciated deeply. In 1985 he died memorable Member. peacefully at his home aged 93. Donegan JF & Krebs HA (1929). Acknowledgements Manometrische Messung der Peptidspaltung. Biochem Z 210, 7–23. It is possible that Donegan’s fertile I would like to thank Sean Lavelle mind, disciplined curiosity and and Ron Whittam for their Donegan JF (1942). Some aspects of muscle experimental prowess were not suggestions. physiology. Ir J Med Sci Sixth Series, 561–571. exploited to the full in Galway and Ian C Roddie Milroy TH & Donegan JF (1919). The role of might have blossomed more plasma proteins in diffusion. Biochem J 27, spectacularly elsewhere. On the Honorary Member, London 258–271.

The Benevolent Fund • A technician diagnosed with Where does the Ben Fund get its incapacitating motor neurone money from? of The Physiological disease had to stop work and also Partly from such activities as the adapt his house. He could not get raffles held at main meetings, but any help at all from his local council Society mainly from generous donations and the Ben Fund obviously could I’d like to tell our Members a little not provide all the money needed from Members of The Society. bit about the Benevolent Fund. (£30K plus), but it could (and did) So what can Society Members do It was originally set up in 1976 ‘ for give enough to help get a wheelchair to help? the purpose of assisting Members of and ramp to enable him to get in and Two things. One, make a donation. The Society and staff and former staff out of the house; These can be one-off, but the most (who by the nature of their • An academic staff member died useful is some form of regular employ -ment can be considered to prematurely without the usual staff donation – it doesn’t need to be have contributed to the advance of pension. (He originally came from abroad and was never enrolled in the much – and is even better if it is physiology) employed at teaching, university’s pension scheme by his done under the Gift Aid scheme so research and industrial employer.) The Ben Fund could not that we can reclaim basic rate tax establishments who are in possibly substitute for a pension but from the Chancellor. Forms for necessitous circumstances and their it could (and did) give some donations are available from Elfa at dependants’. immediate support to help his family The Society’s London office (see through its initial financial It relies almost entirely on difficulties; below). donations from Members of the • A technician in a physiology The second thing you can do is to The Society department has a son with a rare tell us if you know of anyone who The Fund is administered by The genetic disorder which requires full- needs (or even might need) help. Physiological Society, but has time care by his parents. The Fund You can do this quite confidentially separate charitable status with its offered a grant to enable the son’s – just drop a line or email to me or own board of trustees. That means, room to be decorated so that he Elfa at the addresses below. in effect, no administrative costs so could live in a more stimulating environment. The Fund has also all income can be used for its assisted with family holidays so that David Brown primary aim – to support people in the family can get some much- need. Chairman, Benevolent Fund Board of needed time away together; Trustees, Department of Who does it support? • A Member of The Society has a child Pharmacology, University College As its statute implies, not just who suffered from meningitis London, Gower Street, London WC1E leading to profound hearing loss. 6BT Members of The Society but The Fund paid for carpet to be fitted T: +44 (0) 20 7679 7297 anyone who has contributed to into their home, in order to maximize F: +44 (0) 20 7679 4496 physiology and is now in serious the child’s residual hearing. E: [email protected] need. This includes academic staff, researchers, technicians, The main point to all of these is Elfa Wilmot maintenance staff and other that the Ben Fund can act both The Physiological Society, Peer House, support staff. rapidly and (even more important, Verulam Street, London WC1X 8LZ perhaps) sympathetically, with T: +44 (0) 20 7269 5713 What sort of help can it give? minimal ‘bureaucracy’, at a time F: +44 (0) 20 7269 5720 Let me give you a few examples: when help is most needed. E: [email protected]

Physiology News | No. 69 | Winter 2007 | www.physoc.org PARLIAMENTARY AND SCIENTIFIC COMMITTEE PN 47

Is dual funding fit for productivity. Knowledge transfer and economic benefits are more purpose? difficult to quantify. The output of highly educated people into the Ian McGrath and I attended a broader economy is widely regarded Parliamentary and Scientific as the biggest benefit, but income Committee event on the 18 June, Is from activities such as licensing and dual funding of our universities fit for consultancy has grown, patents purpose in the 21st century? Three granted have greatly increased, and speakers were lined up: Rama impressive spin-out companies are Thirunamachandran (Director of now coming out of UK universities. Research and Knowledge Transfer, Sustainability is a key issue, and has HEFCE), Sir Keith O’Nions (Director moved to full economic costing General of Science and Innovation, being used as a mechanism to ensure Department of Trade and Industry) that the research councils pay an and Peter Cotgreave (ex-Director of increased share of project support the Campaign for Science & costs (now 80%, a big improvement Engineering, formerly known as Save influencing funding decisions from on the previous position where they British Science. 2010–2011 and fully informing only paid marginal costs). Remaining funding from 2014. Interestingly, challenges for Government are to Rama kicked off with the case for the some subjects – notably the arts, improve the sustainability of the funding councils. He emphasised humanities, social sciences, system still further, build improved that it had not been a dual funding mathematics and statistics – will incentives for funding to come from system for some time, many continue to be peer review based as other areas such business, and different players were involved in a their publication habits (e.g. streamline peer review. multi-layered funding system. The producing monographs rather than funding and research councils Journal papers), do not lend Cotgreave then set out to try to attempt to work very closely themselves so readily to bibliometric provide a counterbalance to the together to ensure that it does analysis. Rama wrapped up by saying rather rosy picture given by the two operate as a 'dual' rather than a that there will be a big debate over previous Government speakers. He 'duel' system, with the funding the next few years in moving to a agreed that no one would now argue councils paying for the well found long-term sustainable funding and that we do not need a dual support lab, the base on which the rest of the assessment system for science, with system. The role of the research science funding system builds. The key issues, such as the merits of councils in providing direct funding Research Assessment Exercises concentrating/dispersing research for specific projects, plus some of the (RAEs) had proved to be a useful funding and links between research associated support costs, was innovation since their inception in and teaching, needing to be reasonably clear. The role of the 1986, having raised overall research addressed. funding councils was rather fuzzy, quality in the UK (shown by its the definition of what their money is correlation with a rise in the UK share O’Nions pointed out that most for having changed over the years, of world citations) and encouraged countries have a dual mode science but broadly expected to cover more strategic research funding system of some sort, infrastructure, and be able to be management in universities. involving project and core funding spent at university discretion to However, over the years bureaucracy support. The basic value of the dual support potentially important blue and game-playing has built up, and a mode is not in question. Government skies research, research training etc. consensus has developed that the policy is trying to achieve world class In practice it is often used to fill system should be changed after the research in the UK, whilst increasing shortfalls in grants from other next RAE in 2008. There had also knowledge transfer and economic sources, for example charity funding been problems with the assessment benefits and the addressing of that does not provide the same level of applied/user led and multi­ national priorities on energy, climate of support costs as the research disciplinary research. The planned change, ageing population, etc. The councils. It is supposed to provide radical overhaul post-2008 will science funding system needs to be funding for universities to make involve using a more metrics driven sustainable, support the best strategic investments, but for this to system, which will hopefully provide science, attract the best people and happen you need a surplus on a more robust indicators for train them for a range of careers, be budget, it is simply not possible if all international comparisons and flexible and globally competitive. He money is committed to existing reduce the admin load for asked what is the actual state of activities. This modest surplus no academics. It is planned to pilot the play? Research excellence in the UK is longer exists; the reality is that, even new metrics based approach over a good story to tell, the UK is very with radically increased Government the next few years, with it high in world rankings on citation funding for science, the number of

Physiology News | No. 69 | Winter 2007 | www.physoc.org 48 PN PARLIAMENTARY AND SCIENTIFIC COMMITTEE/SOCIETY NEWS institutions and individuals now great deal of time and energy trying PHYSIOLOGICAL SOCIETY chasing this funding has grown so to resolve such issues. The MEETINGS 2008/2009 rapidly that the share per capita has Government speakers also received a actually dropped since the 1980s. lot of flak about how the funding 2008 There have also been significant mechanisms had let down Leeds, UK changes in governmental approach foundation discipline areas such as 17–19 March to science policy in the last few chemistry so badly, that many Cardiac & Respiratory Physiology decades. In the 1960s, Government departments had fallen between the Themed Meeting with a Focused tended to define science policy as support cracks and been forced to Symposium on Determining control of creating the right environment for close. A stark warning from a the cardiovascular system in health research to take place, without member of the House of Lords was and disease: from brain to blood vessel. directing research priorities. Now that biomedical sciences, so vital for Cambridge, UK research objectives are highly this country’s industry, might suffer 14–16 July strategic and directed from the a similar fate if its high lab and Main Annual Meeting. centre through the funding bodies. training costs were not adequately The growing demands on the science supported. O’Nions admitted that Oxford, UK purse have led to the invention of this was a complex problem, and 9–11 September rationing mechanisms for that more needed to be understood Metabolism & Endocrinology apportioning research funding, at about the real costs of supporting Themed meeting with a Focused one level the RAE could be departments. There was a general Symposiun on Orchestration of interpreted as just such a feeling in the room that as a nation metabolism in health and disease. mechanism. The system seems to we need to stop pretending that we Shanghai, China work well for 90% of funded can have a world class education 12–16 September research, but some vital blue sky system on the cheap. We need to be International Workshop on Latest research could be excluded. realistic about what we expect to advances in ion channel techniques achieve, there simply isn’t enough applied to physiological problems. A lively debate ensued, money in the system to pay for all unsurprisingly research funding was our expectations. Beijing, China an issue keenly felt by all the 20–22 October participants. Discussants were A logical extension of the dual Joint International Meeting of The concerned by the 'cliff-face' effect of system, if the funding council stream Physiological Society with the QR funding, where departments is increasingly targeted and is to be Chinese Association for Physiological rated less than 5 get really related by metrics to research Sciences and the Canadian, hammered. Funding tends to be project income and outputs, is to Australian and American concentrated in a small number of accept that we actually have a Physiological Societies. elite institutions. Although this can unitary system. On being asked how King’s College London, UK help develop critical mass and far joined up thinking went, by way 15–17 December increase international profiles, it can of an overview of all research Vascular & Smooth Muscle also exclude newer institutions that funding, the speakers acknowledged Physiology Themed Meeting with a often make the biggest contribution that there was a government Focused Symposium on Vascular to educating students from non­ committee that took such an responses to mechanical stress: cellular middle class backgrounds, students overview on which, for example, the cross -talk and integration. that would really benefit from being funding councils and the DTI, exposed to well supported research. responsible for Research Councils, Even elite institutions struggle; many were represented. The logic of 2009 of our top universities are trading in moving to a unitary system has University College Dublin, Republic budget deficit each year. So-called clearly not escaped this group, of Ireland ring fenced funding has been although there are obstacles to 6–10 July notoriously raided recently, notably implementation such as the current Main Annual Meeting. Primary Care Trusts who took money devolution of funding council but not Woods Hole, MA, USA intended for supporting academic research council streams, let alone September posts in medical schools, and the DTI the likely opposition from many Joint International Meeting with the helping itself to the science budget. interested groups. This is potentially Society of General Physiologists on The dual funding system also has a one of the most interesting and Basic biology and disease of muscle. downside in that when gaps are explosive outcomes of the current identified, it is often difficult to debate on how research throughout resolve who is responsible for the UK is funded. Is dual funding addressing them. O’Nions sought to already dead? For full details of Society Meetings reassure participants on this point, and International Workshops visit saying that funding bodies spend a Liz Bell http://www.physoc.org/meetings.

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Introduction of comes at a time of continued uncertainty about the long-term Undergraduates – registration fees future of income sources for The From 1 January 2008, Council have Society and we believe it is a write an article and agreed that all Members and necessary step for us to take if we are win £500! to ensure the delivery of high quality Affiliates will be required to pay AstraZeneca is generously meetings. These issues were raised registration fees to attend all Society supporting the career at the 2007 Annual General Meeting meetings. This will be combined with development of undergraduates in Glasgow and recently ratified by substantial increases in the fees for studying physiology as part of the Meetings & International non-Members to attend our their degree. From 2008 there will Committee and subsequently meetings. We will also be be two annual prizes for the best Council. introducing an early-bird registration physiology-related articles written deadline for all meetings, and We hope that you appreciate the by undergraduates and published Affiliates will continue to enjoy free rationale for this move and that you in Physiology News. registration up to that deadline. will be aware of the consequent Undergraduate students are improved quality of meetings. This decision has not been taken invited to write articles, suitable lightly and we have set fees at as low Prem Kumar for publication in Physiology News, a rate as we feel that we can. It also Meetings Secretary on topics which might include (but are not limited to): Registration fees for 2008 • summer/final year degree projects; (includes the cost of the welcome reception (if applicable), conference material, • experience of attending a lunch, tea and coffee) for the duration of the meeting, but does not include workshop or conference; accommodation, conference dinner or any additional social events) • what turned you on to physiology; • topical/current physiology-related news items; Fees for Themed Meetings (NO DAY RATES) • outreach activities (e.g. school visits, science festivals); • research groups/activities within the department; • review of a paper that encouraged an interest in physiology. Articles should be submitted by 1 March or 1 September 2008 and should not exceed 1000 words and can include an illustration. Submissions should be sent to Fees for Main Meeting (NO DAY RATES) [email protected] and will be judged on appropriateness of topic and writing style by The Physiological Society’s Chief Executive Officer, the Education and Membership Manager and a member of Physiology News Editorial Board, with agreement from AstraZeneca on the winning article.

Lister Institute Research Prizes 2008 Each prize will be £500 and a Applications are invited from outstanding young researchers in biomedical or related day visit to AstraZeneca’s biological sciences for the Lister Institute Research Prizes 2008. Up to four awards will headquarters in Alderley Park, be made on the basis of originality, quality and potential significance of the research and on the achievements of the applicant. Candidates must have more than 3 and Cheshire (to include UK travel, less than 10 years’ post-doctorial experience on 1 October 2008 and must have dinner and overnight guaranteed employment for the first 3 years of the notional years of the award in any accommodation). not-for-profit institution. Prize winners will receive £200,000 which may be used in any appropriate way to support their research, other than the provision or For full details contact Mike Collis augmentation of personal salary. ([email protected]). For full details and application forms please visit www.lister-institute.org.uk

Completed forms must be returned no later than Friday 7 December 2007

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Biosciences Federation. But that is And what do our real competitors not the point. These societies are do? The Royal Society of Chemistry Are bioscience learned together whether or not they are is also active with young people. part of an umbrella organisation: They also look to create teaching societies ‘not fit for They are 'together' in Team resources. However these are not Bioscience. 'Together' the Team focused on 'analytical chemistry' , purpose’? faces competition for money, ' synthetic organic chemistry', or any students, specialists and other subset of the subject of Competition is an essential part of infrastructure from the arts, the chemistry. Their efforts are the scientific research culture. We humanities and other branches of exclusively focused on chemistry aim to do ‘internationally science and engineering. Team because first and foremost they want competitive’ research and funding is Bioscience has created a competitive to encourage more young people to on a ‘competitive’ basis. In reality, internal market and has sometimes become chemists. Their policy is many laboratories seek to be first lost sight of the real competition. wise. amongst equals because there are few accolades in being the second to Yes, there is a little hyperbole in the Where else is there an internal make a discovery. This is often last sentence – but not much! Let us market? Certainly in policy work – difficult to achieve and highly consider some examples. Quite a and this is partly my fault! Currently competitive laboratories frequently few learned societies have staff it is quite common for the collaborate in order to be first working to get teaching resources Biosciences Federation to respond to together. In some modern biology into schools. My strong impression an enquiry and find that several this collaboration can be on a is that they are informed and Member Organisations have massive global scale. In general we dedicated people doing excellent produced their own response. I shall thrive on competition and jobs. But over and over again I hear work harder to ensure that collaboration: the time to be worried that part of the motivation is to competition with Member is when nobody is interested in expose young people to the words Organisations is reduced but I can’t collaborating with you – it suggests that describe their society – really influence a decision of several that you are uncompetitive and have 'microbiology', 'endocrinology', members to 'do their own thing'. I nothing much to offer. This 'physiology', 'biochemistry', am quite convinced that this is competition is a major driver for the 'ecology' and probably all the other ineffective and therefore a waste of success of science but there are ologies! This is crazy because it is money. Somehow the BSF must occasions when it is unhelpful. I impossible for a single school to take increase its catalytic capacity to get a don’t intend here to review the on all these different resources, unified voice for the biosciences on major 'spats' in the biosciences but provided by different societies, and the major topics that do and will will remark only that the current focused on a separate sub-discipline impact on the future health of our (August 2007) intense competition of the biosciences. The internal discipline. between two F1 racing drivers is not market means that 'microbiology' is exactly improving the morale of their successful if it gets more 'hits' than More broadly, we must now identify team. In summary, competition can ' endocrinology'. Do we really think those areas where Team Bioscience be very positive but this upside can that this form of internal has created an internal market that be replaced rather quickly by a competition is helpful? What we acts as a detriment to success in the negative effect if the competition is really need is more students as a external market. Solutions are inappropriate. whole thinking of the biosciences as possible for both the examples given a career. What we really need is a above. The BSF was established to The motor racing example is relevant bigger and better qualified pool of help provide these solutions and I because the competition is inside a young bioscientists. When we detect that the landscape is single team. The drivers have achieve these goals both the changing in a way that will allow this created an 'internal market' to be the microbiologists and the to happen more readily than in the best. They risk taking their eyes off endocrinologists will get more past. There is increasing awareness the 'external market', which is the recruits – as will everyone else. amongst Member Organisations, and real competition provided by other Intense competition may not teams. In the biosciences we improve team morale sometimes behave like Lewis Hamilton and Fernando Alonso!

There are very many organisations active in the biosciences. I believe that there are at least 80 learned societies and about half of these have come together in the

Physiology News | No. 69 | Winter 2007 | www.physoc.org 52 PN BIOSCIENCES FEDERATION their membership, that a structure convince the kids that physiology is • provide opinion and information to for the biosciences that seemed to actually the only biological science and assist the formulation of public policy; work in the mid 20th century is no all the rest are derivative and therefore • promote wide and open debate, longer appropriate today. Several inferior. My evening was spent loitering involving the wider public where in the House of Commons waiting to appropriate, about the practical and weeks ago I was at an open meeting pounce on Science Minister Ian Pearson ethical issues surrounding develop- where Sir David King (Chief Scientific and convince him that the HEFCE funding ments in the biosciences and their Advisor to the Government) asked in formula for physiology should be double applications. his talk if the severely fractured that of the other biological sciences. bioscience landscape was 'fit for I wholeheartedly agree with all these purpose'! The answer depends on Joking apart, Richard Dyer’s article raises aims and think that the BSF provides an important networking opportunity for which purpose you consider. If the many issues, some that I recognise and some that I don’t. I really don’t believe societies which can facilitate alliances. purpose is for systematists, that societies compete for members; However, I don’t think that these ecologists, physiologists or plant many of us are members of a number of alliances should then necessarily be pathologists to meet to talk about societies and see no conflict between badged under the BSF 'banner'. their work, the answer is a qualified them. Regarding competition in yes. In the practical science context, education specifically –The Physiological The BSF is primarily there to provide a societies are successful 'special Society has been a strong supporter of conduit to Government on policy interest groups'. The 'yes' is the BSF and a major participant in the matters. Should it be the only conduit and is it futile for individual societies to qualified because young people BSF Education Committee, contributing make their own responses to don’t always relate strongly to the our staff to supporting BSF-badged educational events. We are also very Government? To my mind the answer is disciplines around which some active on the Animal Sciences Group , the both yes and no – it all depends on the societies are built and this may be a Journals Working Party and in issue. There are many overarching issues future problem for them. However, contributing to BSF responses to where there is consensus amongst the it is very much harder to answer 'yes' Government. I also seem to recall an societies and where the BSF should co­ if the 'fit for purpose' question refers excellent scientific meeting we just held ordinate the response. There are also to outreach and to engagement with in Glasgow jointly with the British issues where societies will disagree and local, national and European Pharmacological Society and the will want to express the views of their members independently. This may be politicians and opinion formers. Biochemical Society. So maybe we can confusing to Government, but what’s These areas need Team Bioscience. work closely with other societies on an increasing number of intiatives without new about that? Of course Government needing to compete at all. would be easy if everyone agreed about Some competition between learned everything. But one hopes Government societies will remain for the Some important issues that I do has expert scientific civil servants who foreseeable future: the competition recognise in Richard’s article are how can enlighten them about the bioscience for membership is an obvious much we collaborate, with whom and community and its sometimes common, example. However, I do believe that whether the BSF has a role in this. We sometimes diverse viewpoints. there is an increased wish for us all to clearly have common scientific interests with a number of other biomedical As I said, I do recognise some important work together whenever appropriate societies, and I am all in favour of issues in Richard’s article. The distinct­ and possible. The wish was rather working with them whenever it is ions between biological disciplines are theoretical 2 years ago: today I see mutually beneficial. However, 'horses for breaking down and it is sometimes hard much more desire for its courses' applies here. For instance, to determine where, for instance, implementation. I am confident that although the term 'physiology' physiology ends and biochemistry Team Bioscience will be built. Its encompasses all living organisms, our begins. Lurking in this debate is the idea shape and final structure is a little Society is not involved in plant/microbial that working more closely with related uncertain, but I am confident of the research and there are fewer biomedical societies could in the long term lead to merger. I can see this outcome because the need is so opportunities for scientific collaboration with BSF member societies who deal with happening in the future, but when is a great. these areas of biology. However, we do very different question. One 'Doomsday' scenario is that the publishing income Richard Dyer actively collaborate with a number of these societies on common areas of that supports most of the major societies education and publishing. will be eroded so much by open access Do learned societies behave publishing that merger will be the only So I am in favour of working together in way to continue to operate. Should we like racing drivers ? teams as long as the team has added be pro-active and merge whilst we are I re-read Richard Dyer’s interesting value for all members. still strong ? I think these are very article this morning whilst blocking the important questions that our Society access to my local garage with my car to What is the BSF’s role in these should be discussing. But wait a minute – prevent the CEO of the Society of collaborations ? According to its web site merging societies would mean there Endocrinology from filling hers. I then the BSF was established to: would be fewer CEOs; I had better dash had a busy day trying to poach • promote liaison, dialogue and inter­ off and let some tyres down at the BPS Biochemical Society members by offering actions within the diverse community of offices in Angel Gate … them our highly attractive travel grants, bioscientists on common issues that followed by visiting local schools to relate to research and teaching; Mike Collis

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psyche may provide you with some answers. Are you a laboratory animal? An insomniac mouse fears the darkness Do you have an I am a transgenic mouse with emotional, sexual luminescent genes. This causes me problems with insomnia. When they or psychic switch the lights off in the mouse house I glow so brightly that I can’t go problem? to sleep. What can I do? Dr Keith Cormorant will for a molecular biology lab. We have Keith Perhaps rearranging your answer your problems and just been retired from commercial bedding so that it covers your head may provide some relief. give honest advice on life, love, oocyte production and have been re ­ homed, but we can no longer perform Shambo I am disturbed by Keith’s sex and the odd physiological sexually without regular injections of experiment flippant answer; there is such a thing chorionic gonadotrophin. Will we ever as Karma and the universe will have tadpoles of our own? If you are an animal employed in appoint a spiritual nemesis to deal physiological research and would like Keith You need to relax and learn to with Keith’s attitude. There is to discuss an emotional, sexual or relate to each other in a non­ unlimited energy available in the psychological problem please experimental context. There a universe and a driving force that contact Dr Cormorant, an number of web sites that may help to wants you to have the undisturbed interspecies psycho-dynamic enhance your romantic responses sleep that you deserve. May I suggest councillor specialising in psychic (Cheap.Fake.Russian.Viagra.For.Mugs reading my other leaflet Achieving transference and aura balance issues .com and Red Hot Asian Toads.com). emotional stability and cosmic mastery in a range of animal species. using colonic irrigation . Try to think Following a minor misunderstanding Shambo We are all sensual beings positively – you won't need to switch with DEFRA, Dr Cormorant is now spiritually connected to a sensual the lights on to read it. joined 'on the other side' by universe. The aura can be very sensitive to disturbances, death Physiology News new spiritual advisor I am a cloned mouse. Will Shambo the Bull. threats by DEFRA in particular are known to affect the aura and there be a soul for me or will Worried about job security? dampen the libido. I would suggest I need to share? changing to a vegetarian diet, and I am a beagle who smokes cigarettes I am a cloned mouse with a spiritual reading my new leaflet Unlocking the for a living in a tobacco company. I am identity problem. I am identical in every sexual psychopath within! Applied concerned that the new legislation way to my cage mates. My physical self Tantric sex therapy for the amphibian banning smoking in the workplace has been perfectly cloned but what may apply to lab animals. Will I still about my soul? Have our souls been have a job to go to or will my company cloned or will we have to share? outsource my job to a Beagle in Keith I am afraid that I may have to Bangalore. pass you over to Shambo on this one. Keith The Home Office has informed Shambo Since arriving on the other us there are no plans at present to side I have begun an emotionally extend legislation banning smoking fulfilling inter-species relationship in the workplace to dogs. with Dolly the sheep who assures me that every clone has its own Shambo Relax, dogs are freely individual soul. allowed to smoke and consume alcohol on the other side. Cannabis is also legally available and does not Dr Keith Cormorant is a registered lead to spiritual psychosis. charity. Dr Keith Cormorant and Shambo the Bull regret that they are Xenopus toads. In love but is unable to enter into any personal there a psycho-sexual correspondence. Although he harbours problem? no spiritual grudges, Shambo is hoping We are Xenopus tank mates; for the to be reincarnated as administrator of last 3 years we have produced oocytes the DEFRA pension fund.

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David Jordan seminal papers, little kernels heralding imminent revolutions in physiological 1953–2007 knowledge.

David Jordan BSc, PhD, DSc (University of Few of us stumble upon great discoveries Birmingham), Professor of Physiology and Ernest Starling3 wrote that prizes and (UCL, University College London) died honours should not be awarded to the aged 54 on Saturday 30 June 2007 fortunate discoverer, since the joy of following a short illness. Born on 14 April discovery contains its own reward, but 1953, he was the only child of Brenda should be used to console the careful and Harry Jordan. He was raised in scientist, the constant reader, the Jarrow, Tyneside, North East England and corrector of errors, the humble assiduous attended Jarrow Springfield Secondary gardener of the growing tree of School (1964-1971). From 1971-1977 he knowledge whose fruit will come in due studied at the University of Birmingham season. In his brief letter to Nature, receiving a BSc in Biological Sciences Starling might have been writing about (1974) and a PhD (1977) for his studies my future supervisor. David Jordan had a kind heart. God rest this fine scholar. on The termination and excitability of sinus science and medical degree rogrammes, nerve afferents (supervisor Mike Spyer). and served as an undergraduate and James F X Jones higher degree external examiner both In 1980, following a 3 year research within the UK and overseas. 1. Carl Ludwig (1816-1895) wrote in a letter to fellowship in the Physiology Department Setchenow: ‘It is mandatory to be at a place at the University of Birmingham, he David’s numerous contributions to where one feels most free in spirit. Only there moved to a lectureship in the academic life will be missed greatly by one is able to make the greatest progress’. Department of Physiology at the Royal colleagues. David is survived by his Cited in Zimmer H G (1996). Carl Ludwig: the Free Hospital School of Medicine parents and Ken, his partner for more man, his time, his influence. Pflugers Arch 432, (University of London). David was than 30 years. R9-22. promoted to senior lecturer in 1988 and 2. Laurence Sterne (1713-1768). Author of to reader in 1993. He spent a sabbatical Michael P Gilbey The life and opinions of Tristram Shandy, (1988-1989) at the Cardiovascular gentleman. Institute, University of California, San An appreciation by an old student Francisco where he was a Julius H Physiologists of Dublin were shocked to 3. Starling E H (1924). Discovery and research. Comroe Research Fellow. Following his hear of the premature death of this fine Nature 113, 606. promotion to Professor in 1999, and the scientist. David was an authority on merger with UCL, David was made Head autonomic neuro-science, but not an Reminiscences of Department on the Royal Free authoritarian by character. I am not sure exactly when I met Dave Campus. Jordan. It was sometime in the early I was his first PhD student. The 1990s, a few years after I had begun Over the period 1980-1988 David’s interaction between mentor and pupil researching central nerve pathways that primary research association was with was of an old-fashioned type and David control the cardiovascular system. Lynne Mike Spyer. He was awarded his first made me feel free in the laboratory we Weaver (University of Western Ontario, independent research grant in 1983. In shared. This intellectual freedom, so Canada) introduced us at a conference in 1988 he began a research collaboration beloved of Carl Ludwig1 , commenced the US. For a number of reasons, Lynne with Andrew Ramage, funded by the with a digression; David’s grant was for thought Dave was an absolutely lovely Wellcome Trust and British Heart studies on central control of airways but man. She had spent 1979 at the Foundation, which continued until the my doctoral studies wandered into the University of Birmingham, where Dave time of his death. The many papers that vagal control of the heart. Obviously had taught her how to do extracellular flowed from their partnership have David agreed with Laurence Sterne2 that electrophysiology on central neurons, significantly increased our understanding digressions are the sunshine and soul of and he was one of the main reasons that of the role of 5-hydroxytryptamine learning. her year in Birmingham was so much fun. receptors in the central nervous control of cardiovascular function. Of physiological material he was a Through the 1990s, Dave and I met at constant reader and he had an enviable conferences where we shared a number His various review articles, book chapters talent for critical analysis. He was drawn of highly enjoyable scientific and editorial activities (a member of the to papers exhibiting internal consistency, conversations, drinks and dinners. As a Editorial Board of The Journal of logical structure and clarity. In a phrase result, I made my first visit to give a talk Physiology from 1989 to 1996 and a he relished elegance in science. He was at the Department of Physiology at what Senior Editor from 1992 to1994) adept at rapidly uncovering was then the Royal Free Hospital School exemplify David’s scholarship. He was a contradictions or inconsistencies. At of Medicine in 1996. However, my member of the British Heart meetings of our Society when David relationship with Dave did not really Foundation's Project Grants Committee exposed two mutually exclusive begin to 'hot up until around the turn of from 1998 to 2002. statements, he would enquire the century. Although my focus until optimistically which one was correct. then had been spinal cardiovascular David’s input to teaching, examining and David’s farewell gift to me was a copy of control pathways, I was becoming committee work was considerable. He Fulton’s Selected readings in the history of increasingly interested in the medulla. ran a number of courses in both the physiology. It contains small extracts of We began to discuss the possibility of

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setting up in Dave’s laboratory the Investigator. We also received support science and our lives has been profound. method of juxtacellular labelling, which from the Wellcome Trust in the form of a would allow us to examine the anatomy Biomedical Research Collaboration Grant Ida Llewellyn-Smith of neurons in the nucleus of the solitary (9/2002-8/2005) that facilitated a Flinders University, Adelaide, tract (NTS) after they had been number of reciprocal visits between Australia characterized electrophysiologically and Dave’s and my laboratories. pharmacologically. Dave had just received funding from the Wellcome Because Brits think Australia is very far Venetia Franglen Trust for a project on the intracellular away and Australians think that the UK is recording of NTS neurons, so there was within easy reach, I visited Dave’s 1941–2007 no problem in switching to a method laboratory many more times than he I first met Venetia at UCL in 1964, when that would produce a higher yield of visited mine. Being a kind and generous she was a PhD student and I a mere MSc filled cells. person, Dave offered me a bed at his student, and came to know her better as house for the duration of my first visit a friend and colleague when I joined the From our first discussions about and that became our pattern. Most of Physiology Department at King’s. Her collaborating, Dave’s depth of my fondest memories of Dave come work on ion and electrolyte transport in knowledge about central cardiovascular from my stays at 108 Purves Road. We frog skin and fetal sheep and pig skin was and central respiratory control, not only had our favourite restaurants in his a development of work she had started in standard laboratory mammals but also neighbourhood, where we enjoyed many during her PhD at Chelsea College under from a comparative perspective, was memorable meals after working late in the supervision of SE Dicker, a leading particularly impressive. He was also very the lab . At least once during every visit, renal physiologist, who worked on good at explaining the intricacies of NTS we would eat a frozen Indian meal from neurohormones. She also worked with electrophysiology and pharmacology to Sainsbury’s at his kitchen table, drinking Richard Durbin, an eminent gastric a novice ('There are how many 5-HT a bottle of Australian (or any old) red, physiologist, on ouabain binding sites in receptor subtypes in the NTS!') and talking serious science and intermittently gastric mucosa. showed great patience in the face of gossiping our heads off. Dave always had some pretty uninformed questions. a balanced view of life. Regardless of At King’s she became deeply enmeshed These qualities clearly made him such a how busy our schedule was (or how keen in student welfare and was Sub-Dean in respected and well-liked teacher, who in I was to keep working), he made sure the Medical Faculty for 5 or 6 years. She his last years was reviewing the curricula that we took time off to do something was mother confessor to successive and performance of new medical and non-scientific. There were visits to waves of adoring students, as a student­ dental schools in south east Asia. I think stately homes, museums and sights of friendly face in the Medical Faculty. the fact that he was an unassuming boy interest. Our last interlude was a from the north of England with very few wonderful day together at Aylesbury on This led to Venetia’s interest in airs and graces, even when he became our way to the 2005 Physiological curriculum development for medical pre­ the Professor of Physiology at the Royal Society meeting in Bristol. Dave was a clinical studies. She retired from King’s Free and University College Medical keen gardener, and whenever I visited in and with her family, husband Geoffrey School in 1999, also contributed to the spring or summer, a tour of the garden (an ex-physiologist, who ran the empathetic relationships that he had was mandatory, as was a discussion admissions programme at St George’s with students and colleagues. about the neighbour who had someone Hospital Medical School) and two sons, come in every 6 months to scythe the moved to Hereford to become a tutor in Dave employed Gareth Jones on his weeds that invaded her backyard. biology at the Open University and then Wellcome Trust grant and, within weeks, Curriculum Development Facilitator at Gareth and Dave were successfully filling I was always touched by the fact that her alma mater, UCL. NTS neurons with Neurobiotin and doing Dave was a loving and dutiful son, who Living in Hereford allowed her to develop histochemistry to reveal them with regularly telephoned his parents. I was her two other great interests – her family ExtrAvidin-horseradish peroxidase. This also highly amused that he reverted to and her Christian work. She was deeply success made me appreciate another his boyhood accent when he spoke to religious, but carried this lightly. She two of Dave’s admirable scientific them. Although he never said 'Ta-ra' to engaged actively in the life of the qualities. One was that he was truly a me, that was the way his conversations Cathedral as a verger and became technically expert electrophysiologist, with his Mum and Dad always ended. involved in several charities, amongst able to get complex and difficult Dave and I also spoke often by phone and which was Cancer Experience methods up and running when other less I will never forget how his voice lifted Collaborative where she became a accomplished researchers could not. The from a rather flat 'hello' when he realized Research Partner. second was that he was not only willing, he was speaking to a friend. but also able, to follow very detailed instructions given to him by a Venetia was wonderfully friendly, kind, Dave and I worked together for 7 years. good natured, hospitable and generous, neuroanatomist with very exacting During that time, many NTS neurons standards, i.e. me. she devoted huge amounts of her time to were filled by Gareth, Dan and Diana; and others, particularly Geoffrey, who was for a number of brains have yet to be cut and The auspicious beginning to our joint many years, a chronic invalid. She will be processed for immunohistochemistry, so greatly missed. work made by Dave and Gareth became Dave’s input to my research will continue the basis for a major part of my grant for many years to come. application to the National Health and Richard Naftalin Medical Research Council of Australia in Dave’s friends and colleagues speak of With prompts from Ana Ilundain, 2000. This application was funded from him fondly and think of him often. We Department of Physiology, University of 2001 to 2003, with Dave as an Associate miss him terribly. His impact on our Seville, Spain.

Physiology News | No. 69 | Winter 2007 | www.physoc.org 56 PN FROM THE ARCHIVES

100 years ago in J Physiol Returning to Langley, the 1907 paper appeared when he was 55; he had been On the contraction of muscle, in Cambridge since arriving as a 19 year chiefly in relation to the presence old undergraduate in 1871, becoming of 'receptive' substances: Part I College Fellow in 1877, FRS in 1883 and J N Langley. 1907, 36, 347–384 succeeding Michael Foster as Professor in 1903. Langley had also been both chief editor and indeed owner of The Journal of My regular trawl of The Society’s Physiology since 1894. Langley was an publication archives from a century ago experimentalist rather than a theorist. has now arrived at December 1907’s HH Dale in his obituary of Elliott quotes volume 36 (issues 4–5) of The Journal of Langley showed in the paper that the Langley’s credo as follows (Dale, 1961): Physiology. I was initially intrigued by a responsiveness to nicotine was highest in ‘ Make accurate observations and get the facts' , paper from A E Boycott and G C C the regions of the muscle innervated by Damant of the Lister Institute of he would say; ' if you do that the theory ought to nerve fibres, but that nicotine acted on make itself’. Preventive Medicine on … marsh-gas, the muscle – or on the muscle 'receptive hydrogen and carbon dioxide produced in substance', in his terminology – rather Like many eminent scientists of the the alimentary canal of goats, since it than the nerves. Thus the nicotine period Langley was amazingly described an 'airtight steel pressure receptive substance must be productive. In his case this may have chamber of 9500 litres capacity' ! concentrated in the muscle at the nerve reflected a lack of distractions – he lived (Boycott & Damant, 1907). However, I endings – in the motor endplates, as we for much of his adult life in college, only have decided to go for a true landmark would now say. moving out when he married at 50. paper from that volume. This is by John Despite acquiring a wife and daughter Newport Langley (1852–1925) (pictured Langley’s ideas were not universally and a keen interest in gardening, he above), then Professor of Physiology at accepted at the time, and vigorous remained scientifically active as both Cambridge, and is one of a series of his debate ensued over the existence and teacher and researcher until the end of papers that were key in defining the idea role of 'receptive substances'. Maehle has his life. His obituarist in J Physiol, Sir of a 'receptive substance' – or, as we written a fascinating account of how Walter (W M) Fletcher, wrote that would now say, receptors. Langley presented the data contained in Langley 'became unwell … on 31 the 1907 (and subsequent) papers to the October (1925) after giving an early The concept of receptive substances, like 7th International Physiology Conference lecture to a large class of students and many other early discoveries in the (the forerunner of IUPS) in Heidelberg in after examining the results of a long physiology of nervous transmission, was 1907 (Maehle, 2004). Here Langley experiment done on the previous day' heavily dependent on investigations of became involved in a fierce public debate (Fletcher, 1926). This, note, at the age of the actions of natural alkaloids like with Rudolf Magnus, which raged in the 73 … ! Pneumonia followed, and Langley muscarine, nicotine, pilocarpine and physiology journals for several years. died at his home on5 November . He had curare. Many of these were isolated and th done his first teaching at Cambridge wholly or partially purified in the late 19 Although Langley is widely credited with exactly 50 years previously, in 1875, as century, and they were eagerly seized on originating the idea of receptors and of Foster’s Demonstrator in Physiology. by physiologists trying to work out how chemical transmission, it would be Fletcher’s obituary gives an excellent they exerted their effects. remiss not to mention that other flavour of Langley the man and of commentators highlight the role of his th In the 1907 paper Langley reports the Cambridge intellectual life in the late 19 graduate student Thomas Renton Elliott century. results of experiments applying nicotine (1877-1961). As was then the custom, both locally (using a fine sable artist’s Elliott published separately from Langley, Unsurprisingly, much has been written brush to apply drops of solution) and and in a famously prophetic Phys Soc about Langley, Elliott, Dale and the globally to frog skeletal muscles. One of communication from 21 May 1904 (On origins of the ideas of receptors and the attractions of his work is the elegant the action of adrenalin) (Elliott, 1904) he neurotransmission, and this quick use of simple but careful observation and hypothesised: vignette has only scratched the surface. subsequent logical deduction. Parts of it For more detail the historical articles by would make good reading for modern Adrenalin might then be the chemical stimulant Max Bennett (2000) or Tilli Tansey (1991) students as an introduction to liberated on each occasion when the are excellent reading. physiological research. For instance: [sympathetic nervous] impulse arrives at the periphery. There can then be no doubt that the contraction Austin Elliott Elliott later became a close friend of [following local nicotine application] spreads throughout the muscle fibres. The outspread Langley’s immediately previous graduate References student Henry (HH) Dale (1875–1968), might be due either to conduction in the fibres, Bennett MR (2000). Neuropharm 19, or to diffusion of nicotine along the fibres. I take who wrote Elliott’s Royal Society 523–546. the former view for the following reasons: with biographical memoir (Dale, 1961) and Boycott AE & Damant GCC (1907). J Physiol 36, the stronger solutions of nicotine the outspread always gave Elliott much credit for 283–287. of the contraction seems to be too quick for originating the ideas whose pursuit Dale HH (1961). Bio Mem Fellows Roy Soc 7, diffusion to occur throughout the segment… ultimately lead Dale to the 1936 Nobel [and] when nicotine is placed upon a small spot 52–74. Prize for neurotransmission . Elliott did of the muscle, the lateral outspread of the Elliott TR (1904). J Physiol 31, xx–xxi. movement is barely appreciable, and is such as not pursue a career in physiological Fletcher WM (1926). J Physiol 61, 4–15. would naturally result from a trifling outspread research after his PhD, but instead of the nicotine … the longitudinal outspread is, attended medical school, later becoming Maehle A-H (2004). Med Hist 48, 153–174. as I have said, throughout the segment (p. 351). the first Professor of Medicine at UCL. Tansey EM (1991). Clin Autonom Res 1, 63–72 .

Physiology News | No. 69 | Winter 2007 | www.physoc.org

Neuronal mechanisms underlying trunk bending during locomotion. Background recordings are ventral root neurograms obtained from an in vitro isolated neonatal rat spinal cord during fictive locomotion. Coloured lines indicate movement trajectories of the spots labelled on the rat (with corresponding colour codes) following 2D kinematic analysis of movements during an episode of locomotion (from Falgairolle & Cazalets, p. 15)

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