DOCSLIB.ORG

The Effects of Tonic Muscle Pain on the Sympathetic and Somatic Motor Systems in Human

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Effects of Tonic Muscle Pain on the Sympathetic and Somatic Motor Systems in Human The Effects of Tonic Muscle Pain on the Sympathetic and Somatic Motor Systems in Humans Azharuddin Fazalbhoy A thesis in fulfillment of the requirements for the degree of Doctor of Philosophy Prince of Wales Clinical School Faculty of Medicine January 2014 ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed ................................................................. Date .......22/01/2014........................................ ii PLEASE TYPE THE UNIVERSITY OF NEW SOUTH WALES Thesis/Dissertation Sheet Surname or Family name: Fazalbhoy First name: Azharuddin Other name/s: Abbreviation for degree as given in the University calendar: PhD School: Prince of Wales Clinical School Faculty: Medicine Title: The effects of tonic muscle pain on the sympathetic and somatic motor systems in human Abstract 350 words maximum: (PLEASE TYPE) Mechanisms underlying the development of chronic muscle pain in humans remain unknown. Our current understanding is based on experimentation in animals, which has resulted in a multitude of theories to postulate the mechanisms in humans. The vicious cycle theory – a popularised but unsupported theory in humans – suggests that muscle metabolites produced by static muscle contractions stimulate group III and IV muscle nociceptors leading to an excitation of gamma-motoneurons through a reflex mechanism. Increased gamma-motor drive causes intrafusal fibres to contract increasing muscle spindle afferent firing. This activity in turn will raise the activation level in the pool of alpha-motorneurones projecting to the primary muscle increasing resting muscle tonus. Muscle spindle afferents and postganglionic sympathetic outflow to skin and muscle was recorded from healthy subjects using the technique of microneurography. Cardiorespiratory function was measured non-invasively. Muscular pain was induced using a solution of hypertonic saline tonically infused via indwelling cannulae delivered by an infusion pump. The rate of infusion was controlled to ensure subjects experienced mild to moderate pain. Muscle spindle afferents fail to show any change in spontaneous discharge rate in response to tonic muscle pain contradicting the observations and conclusions from animal studies. Sympathetic outflow to skin demonstrated a transient increase followed by a sustained decrease during infusion of hypertonic saline. Sympathetic outflow to muscle demonstrated a dichotomy of responses during muscle pain: half of the subjects showing increasing sympathetic activity, BP, and HR; whilst the others showed decreasing sympathetic activity, BP, and HR. Consistent responses were seen in the same individuals when the study was reproduced in a second recording. This investigation clarifies our understanding of the physiological consequences tonic pain has on sympathetic outflow and muscle spindle afferents in the context of developing chronic muscle pain. There is no apparent evidence to suggest that tonic pain increases the discharge rate of spontaneously active muscle spindle afferents to result in chronic muscle pain as proposed by the “vicious cycle” theory. There is, however, evidence of sustained changes in sympathetic outflow to muscle and skin in response to tonic pain that may contribute to the development of chronic pain. Declaration relating to disposition of project thesis/dissertation I hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only). .................................................................... .............................................................. .....22/01/2014........................ Signature Witness Date The University recognises that there may be exceptional circumstances requiring restrictions on copying or conditions on use. Requests for restriction for a period of up to 2 years must be made in writing. Requests for a longer period of restriction may be considered in exceptional circumstances and require the approval of the Dean of Graduate Research. FOR OFFICE USE ONLY Date of completion of requirements for Award: THIS SHEET IS TO BE GLUED TO THE INSIDE FRONT COVER OF THE THESIS iii ACKNOWLEDGEMENTS I am in tears as I write this. This PhD thesis marks the end of a long journey I began 11 years ago after graduating from high school. It was a difficult time for me, but only a few days after starting university I promised myself to turn it around and aim to achieve excellence. I’ve had tremendous amounts of support along the way; hence, I would like to dedicate this thesis to my family. To my wife Farzana, the last 18 months have been a tremendous struggle for both of us. I cannot thank you enough for your love, patience, and support during this time. I know at times I have been very demanding and unpleasant to be around. Thank you so much for understanding and being patient as I spent countless hours at Neura and at home trying to finish this PhD. I would not have finished this if it weren’t for your support and encouragement. No longer will we spend weekends at home so that I can finish my work. From now on it will be just you and I. To my parents Papa and Mummy, you have by far been my greatest support throughout this journey. You sacrificed everything you had and everything you knew to come to a foreign land and start a new life with only one vision that your children get a good education. I hope I have lived up to your expectations and made you proud by achieving the highest form of tertiary education. There is nothing in this world that I could ever give you that will equate to the amount of love and support you have given me. I make dua that it all comes back to you. To my brother Faris, you have been my greatest inspiration in completing this journey. From my first day at university you have been extremely pushy about me being as motivated, dedicated, and hard working as you are. The pressure was relentless and there were times when you just simply got on my nerves, but I am so grateful that you did because if it weren’t for that pressure I may not be where I am today. Thank you so much for everything you have done for me. Also, thank you to my sister in-law Aliya and my little nephew Zeyaan, cha cha has a PhD now. iv To my lab colleagues Elie, Rania, Cheree, and Rachael, thank you so much for all your help running experiments and more importantly for your friendship. We’ve had the most amazing times together in the lab and at conferences, which simply would not have been the same without you all. I wish you all the best with your future and hope that we can continue our friendship long until we are old and miserable. To my supervisor Ingvars, I am truly grateful for what you have taught me about being a good scientist. Your high standards of scientific research, critical evaluation, and constructive criticism are something to be envious of. Yes, at times they have been over the top and frustrating but I have nothing but respect for you as these qualities have certainly influenced me and have given me a foundation which I believe will give me great success in a career of research. I also thank you for your friendship and support especially in the first 12 months of my PhD. There were times when you literally had to spoon-feed me, but never did you make me feel as if I couldn’t knock on your door and ask for help. Last but not least I would like to thank my supervisor Vaughan, there are simply no words in the English language that can express my gratitude for what you have done for me. I approached you to do a PhD with nothing except a little enthusiasm and motivation and you have helped turn it into a reality. Thank you so much for your advice, your help, your time, and your friendship. I couldn’t have asked for a better PhD supervisor. You truly have made my time as a PhD student an absolute delight. All I can say is when I grow up I want to be like you. v ABSTRACT Mechanisms underlying the development of chronic muscle pain in humans remain unknown. Our current understanding is principally based on experimentation in animals, which has resulted in the formulation of a multitude of theories and physiological models to postulate these mechanisms in humans. The vicious cycle theory – a popularised but unsupported theory in humans – suggests that muscle metabolites produced by static muscle contractions stimulate group III and IV muscle nociceptors leading to an excitation of gamma-motoneurones through a reflex mechanism. Increased gamma-motor drive causes intrafusal fibres to contract increasing muscle spindle afferent firing.
Load more

Recommended publications
  • What's the Connection?
    WHAT’S THE CONNECTION? Sharon Winter Lake Washington High School Directions for Teachers 12033 NE 80th Street Kirkland, WA 98033 SYNOPSIS Students elicit and observe reflex responses and distinguish between types STUDENT PRIOR KNOWL- of reflexes. They then design and conduct experiments to learn more about EDGE reflexes and their control by the nervous system. Before participating in this LEVEL activity students should be able to: Exploration, Concept/Term Introduction Phases ■ Describe the parts of a Application Phase neuron and explain their functions. ■ Distinguish between sensory and motor neurons. Getting Ready ■ Describe briefly the See sidebars for additional information regarding preparation of this lab. organization of the nervous system. Directions for Setting Up the Lab General: INTEGRATION Into the Biology Curriculum ■ Make an “X” on the chalkboard for the teacher-led introduction. ■ Health ■ Photocopy the Directions for Students pages. ■ Biology I, II ■ Human Anatomy and Teacher Background Physiology A reflex is an involuntary neural response to a specific sensory stimulus ■ AP Biology that threatens the survival or homeostatic state of an organism. Reflexes Across the Curriculum exist in the most primitive of species, usually with a protective function for ■ Mathematics animals when they encounter external and internal stimuli. A primitive ■ Physics ■ example of this protective reflex is the gill withdrawal reflex of the sea slug Psychology Aplysia. In humans and other vertebrates, protective reflexes have been OBJECTIVES maintained and expanded in number. Examples are the gag reflex that At the end of this activity, occurs when objects touch the sides students will be able to: or the back of the throat, and the carotid sinus reflex that restores blood ■ Identify common reflexes pressure to normal when baroreceptors detect an increase in blood pressure.
    [Show full text]
  • The Nervous System Reflexes Spinal Reflexes Reflex Arc the Stretch
    1/17/2016 Reflexes • Rapid, involuntary, predictable motor response to a stimulus The Nervous System Spinal Reflexes Spinal Reflexes Reflex Arc • Spinal somatic reflexes • Components of a reflex arc – Integration center is in the spinal cord 1. Receptor—site of stimulus action – Effectors are skeletal muscle 2. Sensory neuron—transmits afferent impulses to the CNS • Testing of somatic reflexes is important clinically 3. Synapses in gray matter—either monosynaptic or to assess the condition of the nervous system polysynaptic region within the CNS 4. Motor neuron—conducts efferent impulses away from cord • Identical stimulus should always elicit the same 5. Effector—muscle fiber or gland cell that responds to response stereotyped reflex the efferent impulses by contracting or secreting Stimulus The Stretch Reflex Skin • Monosynaptic reflex – 2 neurons (sensory and motor), 1 synapse 1 Receptor Interneuron • Muscle spindles 2 Sensory neuron – Sensory receptors in belly of muscle 3 Integration center – Detects changes in length of muscle 4 Motor neuron • Muscle is stretched, reflex reverses the stretch 5 Effector • Important for coordination, maintenance of posture, keeps muscles from over stretching Spinal cord (in cross section) Figure 13.14 1 1/17/2016 Secondary sensory The patellar (knee-jerk) reflex—a specific example of a stretch reflex Efferent (motor) endings (type II fiber – fiber to muscle spindle senses when muscle 2 is still) Quadriceps 3a (extensors) 3b 3b ααα Efferent (motor) 1 Primary sensory fiber to extrafusal Patella endings (type Ia Muscle Spinal cord muscle fibers spindle Fiber – senses (L 2–L4) stretching) Extrafusal muscle 1 Tapping the patellar ligament excites fiber Hamstrings Patellar muscle spindles in the quadriceps.
    [Show full text]
  • Spinal Reflexes
    Spinal Reflexes Lu Chen, Ph.D. MCB, UC Berkeley 1 Simple reflexes such as stretch reflex require coordinated contraction and relaxation of different muscle groups Categories of Muscle Based on Direction of Motion Flexors Æ reduce the angle of joints Extensors Æ increase the angle of joints Categories of Muscle Based on Movement Agonist Æmuscle that serves to move the joint in the same direction as the studied muscle Antagonist Æ muscle that moves the joint in the opposite direction 2 1 Muscle Spindles •Small encapsulated sensory receptors that have a Intrafusal muscle spindle-like shape and are located within the fibers fleshy part of the muscle •In parallel with the muscle fibers capsule •Does not contribute to the overall contractile Sensory force endings •Mechanoreceptors are activated by stretch of the central region Afferent axons •Due to stretch of the whole muscle Efferent axons (including intrafusal f.) •Due to contraction of the polar regions of Gamma motor the intrafusal fibers endings 3 Muscle Spindles Organization 2 kinds of intrafusal muscle fibers •Nuclear bag fibers (2-3) •Dynamic •Static •Nuclear chain fibers (~5) •Static 2 types of sensory fibers •Ia (primary) - central region of all intrafusal fibers •II (secondary) - adjacent to the central region of static nuclear bag fibers and nuclear chain fibers Intrafusal fibers stretched Sensory ending stretched, (loading the spindle) increase firing Muscle fibers lengthens Sensory ending stretched, (stretched) increase firing Spindle unloaded, Muscle fiber shortens decrease firing 4 2 Muscle Spindles Organization Gamma motor neurons innervate the intrafusal muscle fibers. Activation of Shortening of the polar regions gamma neurons of the intrafusal fibers Stretches the noncontractile Increase firing of the center regions sensory endings Therefore, the gamma motor neurons provide a mechanism for adjusting the sensitivity of the muscle spindles.
    [Show full text]
  • Effects of Initial Conditions on the Hoffman Reflex
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.34.3.226 on 1 June 1971. Downloaded from J. Neurol. Neurosurg. Psychiat., 1971, 34, 226-230 Effects of initial conditions on the Hoffman reflex GERALD L. GOTTLIEB AND GYAN C. AGARWAL From the Biomedical Engineering Department, Presbyterian St. Luke's Hospital, Graduate College at the Medical Center, University of Illinois, and the Department of Systems Engineering, University of Illinois at Chicago Circle, Chicago, Illinois, U.S.A. SUMMARY The Hoffmann reflex is a monosynaptic reflex elicited by electrical stimulation of afferent nerve fibres. The amplitude of the reflex response may be measured both by EMG recording from the muscle and by sensing the muscle twitch. These two effects are dependent, not only on the amplitude of the stimulus, but on the state of excitability of the afferent-efferent synaptic pools and on the mechanical state of the muscle. Voluntary control of the stimulated muscle influences these conditions but the effects on the EMG are quite different from those on the twitch. This paper discusses these effects under isometric conditions. The Hoffmann reflex (H-reflex) is a monosynaptic Protected by copyright. reflex induced by electrical stimulation of Ia spindle afferent fibres at intensities below the thresholds of the motor fibres (Hoffmann, 1918; 1922; Magladery and McDougal, 1950; Magladery, Porter, Park, and Teasdall, 1951). It is most easily measured, in man, from the soleus muscle when the tibial nerve is stimulated where it crosses the popliteal fossa. The reflex is manifest electrically and mechanically. Approximately 30 msec after the stimulus, a syn- chronized burst of electromyographic (EMG) activity, the H-wave, is recorded and almost im- mediately thereafter, the gastrocnemius and soleus muscle tensions begin to rise.
    [Show full text]
  • The Plantar Reflex
    THE PLANTAR REFLEX a historical, clinical and electromyographic study From the Department of Neurology, Academic Hospital 'Dijkzigt', Rotterdam, The Netherlands THE PLANTAR REFLEX A HISTORICAL, CLINICAL AND ELECTROMYOGRAPHIC STUDY PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE GENEESKUNDE AAN DE ERASMUS UNIVERSITEIT TE ROTTERDAM OP GEZAG VAN DE RECTOR MAGNIFICUS PROF. DR. B. LEIJNSE EN VOLGENS BESLU!T VAN HET COLLEGE VAN DEKANEN. DE OPENBARE VERDED!GING ZAL PLAATS VINDEN OP WOENSDAG 16 NOVEMBER 1977 DES NAMIDDAGS TE 4.15 UUR PREC!ES DOOR JAN VAN GIJN GEBOREN TE GELDERMALSEN 1977 KRIPS REPRO - MEPPEL PROMOTOR: DR. H. VAN CREVEL CO-PROMOTOR: PROF. DR. A. STAAL CO-REFERENTEN: PROF. DR. H. G. ]. M. KUYPERS PROF. DR. P. E. VOORHOEVE Aan mijn ouders Aan Carien, Maarten en Willem CONTENTS page GENERAL INTRODUCTION 15 CHAPTER I HISTORY OF THE PLANTAR REFLEX AS A CLINICAL SIGN DISCOVERY - the plantar reflex before Babinski 19 - the toe phenomenon . 21 - Joseph Babinski and his work 24 ACCEPTANCE - the pyramidal syndrome before the toe reflex 26 - confirmation . 26 - a curious eponym in Holland 28 - false positive findings? 29 - false negative findings 29 FLEXION AND EXTENSION SYNERGIES - the Babinski sign as part of a flexion synergy . 31 - opposition from Babinski and others . 33 - ipsilateral limb extension with downgoing toes versus the normal plantar response . 36 - crossed toe responses . 36 - tonic plantar flexion of the toes in hemiplegia 37 RIVAL SIGNS - confusion . 39 - different sites of excitation 39 - stretch reflexes of the toe muscles 41 - spontaneous or associated dorsiflexion of the great toe 42 - effects other than in the toes after plantar stimulation 42 THE PLANTAR RESPONSE IN INFANTS - contradictory findings 43 - the grasp reflex of the foot .
    [Show full text]
  • Reflex A18 (1)
    REFLEX A18 (1) Reflex Last updated: April 20, 2019 MONOSYNAPTIC REFLEXES: STRETCH REFLEX ...................................................................................... 1 POLYSYNAPTIC REFLEXES: WITHDRAWAL REFLEX ................................................................................ 7 Reflex - simplest form of coordinated movement - rapid, stereotyped, involuntary (automatic), neurally* mediated response to sensory stimulus (that requires quick reaction at involuntary level). *by relatively simple neuronal network MONOSYNAPTIC REFLEX ARC – sensory neuron synapses directly on motoneuron: POLYSYNAPTIC REFLEX ARC – įsiterpia interneuronai (excitatory or inhibitory) – refleksas gali apimti visą kūną! Some reflexes (esp. spinal and brain stem reflexes) are normally elicited only in DEVELOPING NERVOUS SYSTEM. as higher motor centers mature, these reflexes are suppressed. these reflexes reemerge if damage to higher motor centers occurs (unmasking of such reflexes is good example of hierarchical organization of motor system). MONOSYNAPTIC REFLEXES: stretch reflex STRETCH REFLEX - when skeletal muscle is stretched*, it contracts (short phasic contraction - reflex is also termed phasic stretch reflex) to oppose lengthening. * by tapping tendon with reflex hammer harder muscle is stretched, stronger is reflex contraction. sense organ is muscular spindle. muscles involved in precise movements contain large numbers of spindles (vs. muscles involved in posture maintenance). NEUROTRANSMITTER at central synapse is GLUTAMATE. Reaction time - time between stimulus and response. reaction time in knee jerk is 19-24 ms. REFLEX A18 (2) central delay - time taken to traverse spinal cord (for knee jerk it is 0.6-0.9 ms; since minimal synaptic delay is 0.5 ms, only one synapse could have been traversed). MUSCULAR SPINDLES – fusiform end organ: 3-10 much smaller skeletal muscle fibers (INTRAFUSAL FIBERS) enclosed by capsule: INTRAFUSAL FIBERS: more embryonal in character, have less distinct striations.
    [Show full text]
  • Stretch Reflex & Golgi Tendon Reflex
    NeuroPsychiatry Block Stretch Reflex & Golgi Tendon Reflex By Laiche Djouhri, PhD Dept. of Physiology Email: [email protected] Ext:71044 NeuroPsychiatry Block Chapter 55 Motor Functions of the Spinal Cord, The cord Reflexes (Guyton & Hall) Chapter 3 Neurophysiology (Linda Costanzo) 2 Objectives By the end of this lecture students are expected to: . Describe the components of stretch reflex and Golgi tendon reflex . Differentiate between the functions of muscles spindles and Golgi tendon organ . Explain the roles of alpha and gamma motor neurons in the stretch reflex . Discuss the spinal and supraspinal regulation 10of/6/2016 the stretch reflex 3 What is a Stretch Reflex? . It is a monosynaptic reflex (also known as myotatic reflex) . Is a reflex contraction of muscle resulting from stimulation of the muscle spindle (MS) by stretching the whole muscle . Muscle spindle is the sensory receptor that detects change in muscle length . The classic example of the stretch reflex is the patellar-tendon or knee jerk reflex. What is the significance of stretch reflexes? . They help maintain a normal posture . They function to oppose sudden changes in muscle length 4 10/6/2016 Components of the Stretch Reflex Arc Stretch reflex is a deep Figure 55.5 monosynaptic reflex and its components are: 1. Sensory receptor (muscle spindles) 2. Sensory neuron (group Ia and group II afferents) 3. Integrating center (spinal cord) 4. Motor neurons (α- and γ- spinal motor neurons) 5. Effector (the same muscle This reflex is the simplest; it involves (homonymous) of muscle only 2 neurons & one synapse, spindles) Structure of Muscle Spindles-1 .
    [Show full text]
  • Stretch Reflexes of Triceps Surae in Normal Man
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.45.6.513 on 1 June 1982. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1982;45:513-525 Stretch reflexes of triceps surae in normal man A BERARDELLI, M HALLETT, C KAUFMAN, E FINE, W BERENBERG, SR SIMON From the Rehabilitation Engineering Center at Harvard-MIT, Section ofNeurology, Department ofMedicine, Brigham and Women's Hospital, the Departments ofOrthopedic Surgery and Pediatrics, Children's Hospital Medical Center and the Departments ofNeurology, Orthopedic Surgery and Pediatrics, Harvard Medical School SUMMARY In order to learn more about stretch reflex behaviour of triceps surae, normal human subjects sat in a chair with one foot on a platform attached to a torque motor that produced phasic dorsiflexion displacements of the ankle. EMG activity was recorded from triceps surae and responses were obtained for various conditions. When the subject's foot was relaxed, stretch of triceps surae produced a single EMG component at short-latency which increased in magnitude with increasing velocity of stretch. The response was not altered if the subject was asked to plantarflex or dorsiflex the ankle voluntarily when he felt the perturbation. It was reduced by vibration of the Achilles tendon. If the triceps surae was stretched while the subject plantar- flexed his ankle, the short-latency response was followed by one and sometimes two long-latency responses. Like the short-latency reflex when the foot was relaxed, none of these responses was altered by the subject's planned movement after feeling the perturbation. All of the responses Protected by copyright.
    [Show full text]
  • Muscle Tone Physiology and Abnormalities
    toxins Review Muscle Tone Physiology and Abnormalities Jacky Ganguly , Dinkar Kulshreshtha, Mohammed Almotiri and Mandar Jog * London Movement Disorder Centre, London Health Sciences Centre, University of Western Ontario, London, ON N6A5A5, Canada; [email protected] (J.G.); [email protected] (D.K.); [email protected] (M.A.) * Correspondence: [email protected] Abstract: The simple definition of tone as the resistance to passive stretch is physiologically a complex interlaced network encompassing neural circuits in the brain, spinal cord, and muscle spindle. Disorders of muscle tone can arise from dysfunction in these pathways and manifest as hypertonia or hypotonia. The loss of supraspinal control mechanisms gives rise to hypertonia, resulting in spasticity or rigidity. On the other hand, dystonia and paratonia also manifest as abnormalities of muscle tone, but arise more due to the network dysfunction between the basal ganglia and the thalamo-cerebello-cortical connections. In this review, we have discussed the normal homeostatic mechanisms maintaining tone and the pathophysiology of spasticity and rigidity with its anatomical correlates. Thereafter, we have also highlighted the phenomenon of network dysfunction, cortical disinhibition, and neuroplastic alterations giving rise to dystonia and paratonia. Keywords: spasticity; rigidity; dystonia; paratonia 1. Introduction Muscle tone is a complex and dynamic state, resulting from hierarchical and reciprocal anatomical connectivity. It is regulated by its input and output systems and has critical Citation: Ganguly, J.; Kulshreshtha, interplay with power and task performance requirements. Tone is basically a construct of D.; Almotiri, M.; Jog, M. Muscle Tone motor control, upon which power is intrinsically balanced.
    [Show full text]
  • Analysis of Stretch Reflex Responses in Mice Lacking Munc18-1 in Proprioceptors
    ANALYSIS OF STRETCH REFLEX RESPONSES IN MICE LACKING MUNC18-1 IN PROPRIOCEPTORS A thesis submitted in partial FulFillment oF the requirements For the degree oF Master oF Science By AMR MOHI B.D.S., Cairo University 2009 2017 Wright State University WRIGHT STATE UNIVERSITY GRADUATE SCHOOL DECEMBER 14, 2017 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Amr Mohi ENTITLED Analysis of Stretch RefleX Responses in Mice Lacking Munc18-1 in Proprioceptors BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF Master oF Science. _________________________________________________ David R. Ladle, Ph.D. Thesis Director _________________________________________________ ERIC S. BENNETT, Ph.D. Department Chair Department oF Neuroscience, Cell Biology and Physiology Committee on Final Examination _____________________________________ Mark M. Rich, M.D. Ph.D. _____________________________________ Patrick M. Sonner, Ph.D. _____________________________________ Barry Milligan, Ph.D. Interim Dean oF the Graduate School Abstract Mohi, Amr. M.S. Anatomy Program, Department of Neuroscience, Cell Biology, and Physiology, Wright State University, 2017. Analysis oF Stretch ReFleX Responses In Mice Lacking Munc18-1 In Proprioceptors. The monosynaptic stretch reflex circuit is one of the simplest circuits of the central nervous system. We studied the connection between Ia proprioceptive afferents and motor neurons that comprise the circuit, by stimulating the dorsal root and recording from the ventral root of the fourth lumbar spinal nerve. In our study, we analyzed the status of neurotransmission in the stretch reflex circuit in postnatal PV-cre; munc18-1 lox/lox conditional mutant mice. Munc18-1 is responsible for synaptic vesicular release in neurons. In the PV-cre; Munc18-1 lox/lox mutants we use, Munc18-1 is only knocked out in proprioceptive afferents and A-beta somatosensory afferents, both of which express parvalbumin (PV).
    [Show full text]
  • The History of Reflexes Part 2
    12/15/12 Ev ernote Web The History of Reflexes Part 2 Saturday, December 15 2012, 12:10 PM The History of Reflexes Part 2: From Sherrington to 2004 Citation: Clarac , F (2005) The History of Reflexes Part 2: From Sherrington to 2004, IBRO History of Neuroscience [http://www.ibro.info/Docs_Module/Docs_Main_Form.asp?D=1&LC_Docs_ID=3156] Accessed: date Francois Clarac PART 2: FROM SHERRINGTON TO 2004 During the twentieth century the neurophysiological mechanisms of the reflex has been intensely described in relation to other neuronal functions. We shall analyse these reflex mechanisms in comparison to the development of the neurosciences. Studies on spinal cat reflex physiology were being carried out by Sherrington’s school at the same time as the revolution in nervous system histology was taking place. After the discovery of ‘la reazione nera’ (the black reaction) by Golgi (1843-1926) in 1873, the structure of the CNS gave rise to much debate. There were those who claimed that the nerve cells were all connected together by central networks. Golgi, following J. von Gerlach (1820-96), explained that the relations between two cells are continuous, whereas Waldeyer (1836-1921), in his 1889 review of the ‘neuron theory’, reported that the cell body has short extensions called dendrites, as suggested by His (1831-1904), and one much longer one, called the axon, as suggested by Kolliker (1817-1905). C. Sherrington (1857-1952) named the contacts between contiguous neurons for the first time in 1897 in a textbook edited by M. Foster, where he called them ‘synapses’. Most histologists agreed with this theory, and the greatest of them all was in fact S.
    [Show full text]
  • Deep Tendon Reflexes
    Reflex Physiology Dr. Ali Ebneshahidi © 2009 Ebneshahidi Reflex Physiology . Reflexes are automatic, subconscious response to changes within or outside the body. a. Reflexes maintain homeostasis (autonomic reflexes) – heart rate, breathing rate, blood pressure, and digestion. b. Reflexes also carry out the automatic action of swallowing, sneezing, coughing, and vomiting. c. Reflexes maintain balance & posture. ex. Spinal reflexes – control trunk and limb muscles. d. Brain reflexes – involve reflex center in brain stem. ex. Reflexes for eye movement. © 2009 Ebneshahidi Reflex Arc The reflex arc governs the operation of reflexes. Nerve impulses follow nerve pathways as they travel through the nervous system. The simplest of these pathways, including a few neurons, constitutes a reflex arc. Reflexes whose arc pass through the spinal cord are called spinal reflexes. © 2009 Ebneshahidi Parts of Reflex Arc . 1. Receptor – detects the stimulus. a) Description: the receptor end of a particular dendrite or a specialized receptor cell in a sensory organ. b) function: sensitive to a specific type of internal or external change. 2. sensory neuron – conveys the sensory info. to brain or spinal cord. a. Description: Dendrite, cell body, and axon of a sensory neuron. b. Function: transmit nerve impulses from the receptor into the brain or spinal cord. © 2009 Ebneshahidi Reflex Arc . 3. Interneuron: relay neurons. a. Description: dendrite, cell body, and axon of a neuron within the brain or spinal cord. b. function: serves as processing center, conducts nerve impulses from the sensory neuron to a motor neuron. 4. Motor neuron: conduct motor output to the periphery. a. Description: Dendrite, cell body, and axon of a motor neuron.
    [Show full text]