The Thalamus
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Cortex and Thalamus Lecture.Pptx
Cerebral Cortex and Thalamus Hyperbrain Ch 2 Monica Vetter, PhD January 24, 2013 Learning Objectives: • Anatomy of the lobes of the cortex • Relationship of thalamus to cortex • Layers and connectivity of the cortex • Vascular supply to cortex • Understand the location and function of hypothalamus and pituitary • Anatomy of the basal ganglia • Primary functions of the different lobes/ cortical regions – neurological findings 1 Types of Cortex • Sensory (Primary) • Motor (Primary) • Unimodal association • Multimodal association - necessary for language, reason, plan, imagine, create Note: • Gyri • Sulci • Fissures • Lobes 2 The Thalamus is highly interconnected with the cerebral cortex, and handles most information traveling to or from the cortex. “Specific thalamic Ignore nuclei” – have well- names of defined sensory or thalamic nuclei for motor functions now - A few Other nuclei have will more distributed reappear later function 3 Thalamus Midbrain Pons Limbic lobe = cingulate gyrus Structure of Neocortex (6 layers) white matter gray matter Pyramidal cells 4 Connectivity of neurons in different cortical layers Afferents = inputs Efferents = outputs (reciprocal) brainstem etc Eg. Motor – Eg. Sensory – more efferent more afferent output input Cortico- cortical From Thalamus To spinal cord, brainstem etc. To Thalamus Afferent and efferent connections to different ….Depending on whether they have more layers of cortex afferent or efferent connections 5 Different areas of cortex were defined by differences in layer thickness, and size and -
The Human Thalamus Is an Integrative Hub for Functional Brain Networks
5594 • The Journal of Neuroscience, June 7, 2017 • 37(23):5594–5607 Behavioral/Cognitive The Human Thalamus Is an Integrative Hub for Functional Brain Networks X Kai Hwang, Maxwell A. Bertolero, XWilliam B. Liu, and XMark D’Esposito Helen Wills Neuroscience Institute and Department of Psychology, University of California, Berkeley, Berkeley, California 94720 The thalamus is globally connected with distributed cortical regions, yet the functional significance of this extensive thalamocortical connectivityremainslargelyunknown.Byperforminggraph-theoreticanalysesonthalamocorticalfunctionalconnectivitydatacollected from human participants, we found that most thalamic subdivisions display network properties that are capable of integrating multi- modal information across diverse cortical functional networks. From a meta-analysis of a large dataset of functional brain-imaging experiments, we further found that the thalamus is involved in multiple cognitive functions. Finally, we found that focal thalamic lesions in humans have widespread distal effects, disrupting the modular organization of cortical functional networks. This converging evidence suggests that the human thalamus is a critical hub region that could integrate diverse information being processed throughout the cerebral cortex as well as maintain the modular structure of cortical functional networks. Key words: brain networks; diaschisis; functional connectivity; graph theory; thalamus Significance Statement The thalamus is traditionally viewed as a passive relay station of information from sensory organs or subcortical structures to the cortex. However, the thalamus has extensive connections with the entire cerebral cortex, which can also serve to integrate infor- mation processing between cortical regions. In this study, we demonstrate that multiple thalamic subdivisions display network properties that are capable of integrating information across multiple functional brain networks. Moreover, the thalamus is engaged by tasks requiring multiple cognitive functions. -
Basal Ganglia Anatomy, Physiology, and Function Ns201c
Basal Ganglia Anatomy, Physiology, and Function NS201c Human Basal Ganglia Anatomy Basal Ganglia Circuits: The ‘Classical’ Model of Direct and Indirect Pathway Function Motor Cortex Premotor Cortex + Glutamate Striatum GPe GPi/SNr Dopamine + - GABA - Motor Thalamus SNc STN Analagous rodent basal ganglia nuclei Gross anatomy of the striatum: gateway to the basal ganglia rodent Dorsomedial striatum: -Inputs predominantly from mPFC, thalamus, VTA Dorsolateral striatum: -Inputs from sensorimotor cortex, thalamus, SNc Ventral striatum: Striatal subregions: Dorsomedial (caudate) -Inputs from vPFC, hippocampus, amygdala, Dorsolateral (putamen) thalamus, VTA Ventral (nucleus accumbens) Gross anatomy of the striatum: patch and matrix compartments Patch/Striosome: -substance P -mu-opioid receptor Matrix: -ChAT and AChE -somatostatin Microanatomy of the striatum: cell types Projection neurons: MSN: medium spiny neuron (GABA) •striatonigral projecting – ‘direct pathway’ •striatopallidal projecting – ‘indirect pathway’ Interneurons: FS: fast-spiking interneuron (GABA) LTS: low-threshold spiking interneuron (GABA) LA: large aspiny neuron (ACh) 30 um Cellular properties of striatal neurons Microanatomy of the striatum: striatal microcircuits • Feedforward inhibition (mediated by fast-spiking interneurons) • Lateral feedback inhibition (mediated by MSN collaterals) Basal Ganglia Circuits: The ‘Classical’ Model of Direct and Indirect Pathway Function Motor Cortex Premotor Cortex + Glutamate Striatum GPe GPi/SNr Dopamine + - GABA - Motor Thalamus SNc STN The simplified ‘classical’ model of basal ganglia circuit function • Information encoded as firing rate • Basal ganglia circuit is linear and unidirectional • Dopamine exerts opposing effects on direct and indirect pathway MSNs Basal ganglia motor circuit: direct pathway Motor Cortex Premotor Cortex Glutamate Striatum GPe GPi/SNr Dopamine + GABA Motor Thalamus SNc STN Direct pathway MSNs express: D1, M4 receptors, Sub. -
History of Physics Group Newsletter No 21 January 2007
History of Physics Group Newsletter No 21 January 2007 Cover picture: Ludwig Boltzmann’s ‘Bicykel’ – a piece of apparatus designed by Boltzmann to demonstrate the effect of one electric circuit on another. This, and the picture of Boltzmann on page 27, are both reproduced by kind permission of Dr Wolfgang Kerber of the Österreichische Zentralbibliothek für Physik, Vienna. Contents Editorial 2 Group meetings AGM Report 3 AGM Lecture programme: ‘Life with Bragg’ by John Nye 6 ‘George Francis Fitzgerald (1851-1901) - Scientific Saint?’ by Denis Weaire 9 ‘Benjamin Franklin (1706-1790) - a brief biography by Peter Ford 15 Reports Oxford visit 24 EPS History of physics group meeting, Graz, Austria 27 European Society for the History of Science - 2nd International conference 30 Sir Joseph Rotblat conference, Liverpool 35 Features: ‘Did Einstein visit Bratislava or not?’ by Juraj Sebesta 39 ‘Wadham College, Oxford and the Experimental Tradition’ by Allan Chapman 44 Book reviews JD Bernal – The Sage of Science 54 Harwell – The Enigma Revealed 59 Web report 62 News 64 Next Group meeting 65 Committee and contacts 68 2 Editorial Browsing through a copy of the group’s ‘aims and objectives’, I notice that part of its aims are ‘to secure the written, oral and instrumental record of British physics and to foster a greater awareness concerning the history of physics among physicists’ and I think that over the years much has been achieved by the group in tackling this not inconsiderable challenge. One must remember, however, that the situation at the time this was written was very different from now. -
Clones in the Chick Diencephalon Contain Multiple Cell Types and Siblings Are Widely Dispersed
Development 122, 65-78 (1996) 65 Printed in Great Britain © The Company of Biologists Limited 1996 DEV8292 Clones in the chick diencephalon contain multiple cell types and siblings are widely dispersed Jeffrey A. Golden1,2 and Constance L. Cepko1,3 1Department of Genetics, Harvard Medical School, 2Department of Pathology, Brigham and Women’s Hospital, and 3Howard Hughes Medical Institute, 200 Longwood Avenue, Boston, MA 02115, USA SUMMARY The thalamus, hypothalamus and epithalamus of the ver- clones dispersed in all directions, resulting in sibling cells tebrate central nervous system are derived from the populating multiple nuclei within the diencephalon. In embryonic diencephalon. These regions of the nervous addition, several distinctive patterns of dispersion were system function as major relays between the telencephalon observed. These included clones with siblings distributed and more caudal regions of the brain. Early in develop- bilaterally across the third ventricle, clones that originated ment, the diencephalon morphologically comprises distinct in the lateral ventricle, clones that crossed neuromeric units known as neuromeres or prosomeres. As development boundaries, and clones that crossed major boundaries of proceeds, multiple nuclei, the functional and anatomical the developing nervous system, such as the diencephalon units of the diencephalon, derive from the neuromeres. It and mesencephalon. These findings demonstrate that prog- was of interest to determine whether progenitors in the enitor cells in the diencephalon are multipotent and that diencephalon give rise to daughters that cross nuclear or their daughters can become widely dispersed. neuromeric boundaries. To this end, a highly complex retroviral library was used to infect diencephalic progeni- tors. Retrovirally marked clones were found to contain Key words: cell lineage, central nervous system, diencephalon, neurons, glia and occasionally radial glia. -
The Thalamus: Gateway to the Mind Lawrence M
Overview The thalamus: gateway to the mind Lawrence M. Ward∗ The thalamus of the brain is far more than the simple sensory relay it was long thought to be. From its location at the top of the brain stem it interacts directly with nearly every part of the brain. Its dense loops into and out of cortex render it functionally a seventh cortical layer. Moreover, it receives and sends connections to most subcortical areas as well. Of course it does function as a very sophisticated sensory relay and thus is of vital importance to perception. But also it functions critically in all mental operations, including attention, memory, and consciousness, likely in different ways for different processes, as indicated by the consequences of damage to its various nuclei as well as by invasive studies in nonhuman animals. It plays a critical role also in the arousal system of the brain, in emotion, in movement, and in coordinating cortical computations. Given these important functional roles, and the dearth of knowledge about the details of its nonsensory nuclei, it is an attractive target for intensive study in the future, particularly in regard to its role in healthy and impaired cognitive functioning. © 2013 John Wiley & Sons, Ltd. How to cite this article: WIREs Cogn Sci 2013. doi: 10.1002/wcs.1256 INTRODUCTION and other animals can do quite well without major chunks of cortex. Indeed, decorticate rats behave very pen nearly any textbook of neuroscience or similarly to normal rats in many ways,2 whereas sensation and perception and you will find the O de-thalamate rats die. -
Lecture 12 Notes
Somatic regions Limbic regions These functionally distinct regions continue rostrally into the ‘tweenbrain. Fig 11-4 Courtesy of MIT Press. Used with permission. Schneider, G. E. Brain structure and its Origins: In the Development and in Evolution of Behavior and the Mind. MIT Press, 2014. ISBN: 9780262026734. 1 Chapter 11, questions about the somatic regions: 4) There are motor neurons located in the midbrain. What movements do those motor neurons control? (These direct outputs of the midbrain are not a subject of much discussion in the chapter.) 5) At the base of the midbrain (ventral side) one finds a fiber bundle that shows great differences in relative size in different species. Give examples. What are the fibers called and where do they originate? 8) A decussating group of axons called the brachium conjunctivum also varies greatly in size in different species. It is largest in species with the largest neocortex but does not come from the neocortex. From which structure does it come? Where does it terminate? (Try to guess before you look it up.) 2 Motor neurons of the midbrain that control somatic muscles: the oculomotor nuclei of cranial nerves III and IV. At this level, the oculomotor nucleus of nerve III is present. Fibers from retina to Superior Colliculus Brachium of Inferior Colliculus (auditory pathway to thalamus, also to SC) Oculomotor nucleus Spinothalamic tract (somatosensory; some fibers terminate in SC) Medial lemniscus Cerebral peduncle: contains Red corticospinal + corticopontine fibers, + cortex to hindbrain fibers nucleus (n. ruber) Tectospinal tract Rubrospinal tract Courtesy of MIT Press. Used with permission. Schneider, G. -
Thomas Willis and the Fevers Literature of the Seventeenth Century
Medical History, Supplement No. 1, 1981: 45-70 THOMAS WILLIS AND THE FEVERS LITERATURE OF THE SEVENTEENTH CENTURY by DON G. BATES* WE NEED not take literally the "common Adagy Nemo sine febri moritur," even for seventeenth-century England.' Nor is it likely that Fevers put "a period to the lives of most men".2 Nevertheless, the prevalence and importance of this "sad, comfortless, truculent disease" in those times cannot be doubted. Thomas Willis thought that Fevers had accounted for about a third of the deaths of mankind up to his day, and his contemporary and compatriot, if not his friend, Thomas Sydenham, guessed that two- thirds of deaths which were not due to violence were the result of that "army of pestiferous diseases", Fevers.3 These estimates are, of course, based almost entirely on impressions.4 But such impressions form the subject of this paper, for it is the contemporary Fevers literature upon which I wish to focus attention, the literature covering little more than a century following the death of the influential Jean Fernel in 1558. In what follows, I shall poke around in, rather than survey, the site in which this literature rests, trying to stake out, however disjointedly and incompletely, something of the intellectual, social, and natural setting in which it was produced. In keeping with the spirit of this volume, this is no more than an exploratory essay of a vast territory and, even so, to make it manageable, I have restricted myself largely to *Don G. Bates, M.D., Ph.D., Department of Humanities and Social Studies in Medicine. -
Diencephalon Sists of the Midbrain, Pons, and Medulla
Diencephalon The brain lies within the cranial cavity of the skull and is made up of billions of nerve cells (neu - rons) and supporting cells (glia) . Neuronal cell bodies group together as gray matter, and their processes group together as white matter. The brain can be divided into four main parts: the cerebrum, diencephalon, brain stem, and cere - bellum. • The cerebrum is the largest part of the brain and consists of the four paired lobes with the two cerebral hemispheres, connected by a mass of white matter called the corpus callosum. The cerebrum accounts for about 80% of the brain’s mass and is concerned with higher functions, including perception of sensory impulses, instigation of voluntary movement, memory, thought, and reasoning. There are two layers of the cerebrum: - The cerebral cortex is the thin, wrinkled gray matter covering each hemisphere - The cerebral medulla is a thicker core of white matter • The diencephalon lies beneath the cerebral hemispheres and has two main structures ¾ the thalamus and the hypothalamus. The walnut-sized thalamus is a large mass of gray matter that lies on either side of the third ventricle. The thalamus is a great relay station on the afferent sen - sory pathway to the cerebral cortex. The tiny hypothalamus forms the lower part of the lateral wall and floor of the third ventricle. The hypothalamus exerts an influence on a wide range of body functions. • The cerebellum is attached to the brain and features a highly folded surface. It is important in the control of movement and balance. • The brainstem is the lower extension of the brain where it connects to the spinal cord. -
Willis and the Virtuosi
Forum on Public Policy The Scientific Method through the Lens of Neuroscience; From Willis to Broad J. Lanier Burns, Professor, Research Professor of Theological Studies, Senior Professor of Systematic Theology, Dallas Theological Seminar Abstract: In an age of unprecedented scientific achievement, I argue that the neurosciences are poised to transform our perceptions about life on earth, and that collaboration is needed to exploit a vast body of knowledge for humanity’s benefit. The scientific method distinguishes science from the humanities and religion. It has evolved into a professional, specialized culture with a common language that has synthesized technological forces into an incomparable era in terms of power and potential to address persistent problems of life on earth. When Willis of Oxford initiated modern experimentation, ecclesial authorities held intellectuals accountable to traditional canons of belief. In our secularized age, science has ascended to dominance with its contributions to progress in virtually every field. I will develop this transition in three parts. First, modern experimentation on the brain emerged with Thomas Willis in the 17th Century. A conscientious Anglican, he postulated a “corporeal soul,” so that he could pursue cranial research. He belonged to a gifted circle of scientifically minded scholars, the Virtuosi, who assisted him with his Cerebri anatome. He coined a number of neurological terms, moved research from the traditional humoral theory to a structural emphasis, and has been remembered for the arterial structure at the base of the brain, the “Circle of Willis.” Second, the scientific method is briefly described as a foundation for understanding its development in neuroscience. -
05 Trigeminal System 2013.Pdf
Dental Neuroanatomy Thursday February 7th, 2013 David A. Morton, Ph.D. 5. THE TRIGEMINAL SYSTEM Somatic Sensation of the Face and Head Objectives 1. Outline the two pathways for facial sensation from the head. 2. Contrast facial sensation from the head and somatic sensation from the body. In what ways are they similar? Different? Try drawing this on the Haines atlas diagram at the end of the lecture. 3. Diagram the corneal reflex: the afferent and efferent limbs as well as nuclei involved in the brainstem. 4. If a person does not blink, how would you determine if the problem were in the sensory (afferent) limb, motor (efferent) limb, or brainstem interconnections for the corneal reflex? 5. Explain how a single, small medullary vascular lesion could abolish pain and temperature from the face on the right side and pain and temperature from the body on the left side. What vessel is most likely occluded? Introduction – The trigeminal system for the face and oral cavity is organized in a manner similar to the spinal cord. It has the equivalent of both the DCML pathway and the ALS pathway. The two trigeminal pathways will converge in the thalamus. The most confusing thing is that one of them descends before crossing and the other crosses immediately. Peripheral Receptors and Sensation Structures served by trigeminal system. 1. Cornea 2. Mucocutaneous tissues around mouth and nostrils. 3. Oral and nasal mucosae 4. Paranasal sinuses 5. Tongue (anterior two thirds) 6. Teeth and gums 7. Dura of anterior and middle cranial fossae 8. Skin of face to the vertex except angle of jaw 9. -
Library Exhibition
LIBRARY EXHIBITION DRAMATIS PERSONAE William Cole (1635-1716): Physician in Henry Sampson (1629-1700): Historian of the Worcester. Author of a treatise on the se- dissenters and physician to non- cretions of animals. conformists in London. Contributor to the Sir John Floyer (1649-1734): Physician in Philosophical Transactions of the Royal Society. Lichfield. Author of works on asthma, John Wilkins (1614-1672): A cadaver. Once therapeutic bathing, and enthusiast for tak- Bishop of Chester. Founder member of the ing a patient’s pulse. Royal Society. Popularizer of Galileo. Crea- Richard Higgs (ca. 1632-1690): A physician in tor of a universal language. Coventry. Supplier to the pesthouse there. Thomas Willis (1621-1675): Physician in Ox- Richard Lower (1631-1691): Physician in ford. Associate of Messrs Boyle, Wren, London. Author of a major work on the Locke, Hooke. Writer of pioneering work heart and circulatory system, performed the on the brain. Sedleian Professor of Natural first successful blood-transfusion on two Philosophy at Oxford. dogs. Walter Needham (1631?-1691?): Anatomical lecturer to the Company of Surgeons. Au- thor of a work on foetal anatomy. The Medical Correspondence of Richard Higgs Gathered together in a single album kept here in the Library are a selection of letters from numerous key figures of the late 17th century flowering of scientific and medical thought and discovery that took place in Oxford. All of these letters are addressed to Dr Richard Higgs, and yet, for an associate of such illustrious figures, Higgs himself is elusive in the historical record. Originally from Gloucestershire, he appears to have matriculated at Queen’s College in Oxford in 1642 at around the age of 17, before embarking on medical training at Hart Hall, to graduate DM in 1659.