DOCSLIB.ORG

Cortical Mechanisms of Adaptation in Auditory Processing

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cortical Mechanisms of Adaptation in Auditory Processing University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2017 Cortical Mechanisms Of Adaptation In Auditory Processing Ryan Natan University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Neuroscience and Neurobiology Commons Recommended Citation Natan, Ryan, "Cortical Mechanisms Of Adaptation In Auditory Processing" (2017). Publicly Accessible Penn Dissertations. 2498. https://repository.upenn.edu/edissertations/2498 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/2498 For more information, please contact [email protected]. Cortical Mechanisms Of Adaptation In Auditory Processing Abstract Adaptation is computational strategy that underlies sensory nervous systems’ ability to accurately encode stimuli in various and dynamic contexts and shapes how animals perceive their environment. Many questions remain concerning how adaptation adjusts to particular stimulus features and its underlying mechanisms. In Chapter 2, we tested how neurons in the primary auditory cortex adapt to changes in stimulus temporal correlation. We used chronically implanted tetrodes to record neuronal spiking in rat primary auditory cortex during exposure to custom made dynamic random chord stimuli exhibiting different levels of temporal correlation. We estimated linear non-linear model for each neuron at each temporal correlation level, finding that neurons compensate for temporal correlation changes through gain-control adaptation. This experiment extends our understanding of how complex stimulus statistics are encoded in the auditory nervous system. In Chapter 3 and 4, we tested how interneurons are involved in adaptation by optogenetically suppressing parvalbumin-positive (PV) and somatostatin- positive (SOM) interneurons during tone train stimuli and using silicon probes to record neuronal spiking in mouse primary auditory cortex. In Chapter 3, we found that inhibition from both PVs and SOMs contributes to stimulus-specific adaptation (SSA) through different mechanisms. SOM inhibition was stimulus-specific, suppressing responses to standard tones more strongly than responses to deviant tones, and increasing with standard tone repetition. PVs amplified SSA because inhibition was similar for standard and deviant tones and PV mediated inhibition was insensitive to tone repetition. PVs and SOMs themselves exhibit SSA, and a Wilson-Cowan dynamic model identified that PVs and SOMs can directly contribute to SSA in pyramidal neurons. In Chapter 4, we tested how SOMs and PVs inhibition is modulated with the dynamics of adaptation and across frequency tuning, during exposure to single frequency tone trains across the neuron’s tuning curve. We found that the magnitude of SOM inhibition correlated with the magnitude of adaptive suppression, while PVs inhibition was largely insensitive to stimulus conditions. Together Chapters 3 and 4 implicate SOM inhibition in actively suppressing responses in a stimulus-specific manner while PV inhibition may passively enhance stimulus-specific suppression. These experiments inform the underlying principles and mechanisms of cortical sensory adaptation. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Neuroscience First Advisor Maria N. Geffen Keywords Adaptation, Auditory, Cortex, Inhibition, Interneuron Subject Categories Neuroscience and Neurobiology This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/2498 CORTICAL MECHANISMS OF ADAPTATION IN AUDITORY PROCESSING Ryan G Natan A DISSERTATION In Neuroscience Presented to the Faculties of the University of Pennsylvania In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2017 Supervisor of Dissertation ________________________ Maria Neimark Geffen, PhD Assistant Professor of Otorhinolaryngology Graduate Group Chairperson ________________________ Joshua I. Gold, PhD Professor of Neuroscience Dissertation Committee Yale Cohen, Associate Professor of Otorhinolaryngology Diego Contreras, Professor of Neuroscience Christopher Fang-Yen, Assistant Professor of Neuroscience Robert Froemke, Assistant Professor of Otolaryngology, Physiology & Neuroscience, NYU This dissertation is dedicated to my family. I simply could not have achieved my goals without the boundless love and support of my mother, father, brother, and especially my wife Kathy. Thanks, I love you! ii ACKNOWLEDGMENTS I would like to express my utmost gratitude to my advisor, Maria Neimark Geffen, for providing fantastic mentorship in my education, lab work and scientific career. It has been a wonderful experience to learn and grow under the guidance of a genuine friend and inspiring individual. Thanks to Yale Cohen, Diego Contreras, Chris Fang-Yen and Robert Froemke for serving on my thesis committee and helping me make the most of my graduate training. Thanks in addition to Mark Aizenberg, Jennifer Blackwell, John Briguglio, Isaac Carruthers, Laetitia Mwilambwe- Tshilobo, Winnie Rao, and current and former members of the Geffen Lab – it has been a great pleasure working with you. Thanks finally to the students, faculty and administration of the Neuroscience Graduate Group, who have cultivated a uniquely rewarding graduate training experience. iii ABSTRACT CORTICAL MECHANISMS OF ADAPTATION IN AUDITORY PROCESSING Ryan G Natan Maria Neimark Geffen Adaptation is computational strategy that underlies sensory nervous systems’ ability to accurately encode stimuli in various and dynamic contexts and shapes how animals perceive their environment. Many questions remain concerning how adaptation adjusts to particular stimulus features and its underlying mechanisms. In Chapter 2, we tested how neurons in the primary auditory cortex adapt to changes in stimulus temporal correlation. We used chronically implanted tetrodes to record neuronal spiking in rat primary auditory cortex during exposure to custom made dynamic random chord stimuli exhibiting different levels of temporal correlation. We estimated linear non-linear model for each neuron at each temporal correlation level, finding that neurons compensate for temporal correlation changes through gain-control adaptation. This experiment extends our understanding of how complex stimulus statistics are encoded in the auditory nervous system. In Chapter 3 and 4, we tested how interneurons are involved in adaptation by optogenetically suppressing parvalbumin-positive (PV) and somatostatin- positive (SOM) interneurons during tone train stimuli and using silicon probes to record neuronal spiking in mouse primary auditory cortex. In Chapter 3, we found that inhibition from both PVs and SOMs contributes to stimulus-specific adaptation (SSA) through different mechanisms. SOM inhibition was stimulus-specific, suppressing iv responses to standard tones more strongly than responses to deviant tones, and increasing with standard tone repetition. PVs amplified SSA because inhibition was similar for standard and deviant tones and PV mediated inhibition was insensitive to tone repetition. PVs and SOMs themselves exhibit SSA, and a Wilson-Cowan dynamic model identified that PVs and SOMs can directly contribute to SSA in pyramidal neurons. In Chapter 4, we tested how SOMs and PVs inhibition is modulated with the dynamics of adaptation and across frequency tuning, during exposure to single frequency tone trains across the neuron’s tuning curve. We found that the magnitude of SOM inhibition correlated with the magnitude of adaptive suppression, while PVs inhibition was largely insensitive to stimulus conditions. Together Chapters 3 and 4 implicate SOM inhibition in actively suppressing responses in a stimulus-specific manner while PV inhibition may passively enhance stimulus-specific suppression. These experiments inform the underlying principles and mechanisms of cortical sensory adaptation. v TABLE OF CONTENTS DEDICATIONS ...................................................................................................................... II ACKNOWLEDGMENTS ........................................................................................................ III ABSTRACT ........................................................................................................................... IV TABLE OF CONTENTS.......................................................................................................... VI LIST OF FIGURES ............................................................................................................... VIII 1. INTRODUCTION ............................................................................................................... 1 The roles of adaptation in auditory sensation ................................................................................................ 2 Adaptation in models of sensory encoding ..................................................................................................... 8 Inhibitory interneurons ................................................................................................................................. 11 Inhibition in adaptation ................................................................................................................................. 14 Bibliography .................................................................................................................................................. 18
Load more

Recommended publications
  • Neural Interfacing Architecture Enables Enhanced Motor Control and Residual Limb Functionality Postamputation
    Neural interfacing architecture enables enhanced motor control and residual limb functionality postamputation Shriya S. Srinivasana,b,c,1, Samantha Gutierrez-Arangoa, Ashley Chia-En Tengd, Erica Israela, Hyungeun Songa,b, Zachary Keith Baileya,e, Matthew J. Cartya,f,c, Lisa E. Freeda,b, and Hugh M. Herra,c,1 aMIT Center for Extreme Bionics, Biomechatronics Group, Massachusetts Institute of Technology, Cambridge, MA 02139; bHarvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139; cHarvard Medical School, Boston, MA 02114; dDepartment of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139; eDepartment of Mechanical Engineering, United States Air Force Academy, Colorado Springs, CO 80920; and fDivision of Plastics and Reconstructive Surgery, Brigham and Women’s Hospital, Boston, MA 02114 Edited by Peter L. Strick, University of Pittsburgh, Pittsburgh, PA, and approved December 30, 2020 (received for review September 16, 2020) Despite advancements in prosthetic technologies, patients with excurse, causing cocontraction of muscles and changing gait amputation today suffer great diminution in mobility and quality patterns (11–14). Together, these peripheral and central modi- of life. We have developed a modified below-knee amputation fications result in the poor production of efferent signals for (BKA) procedure that incorporates agonist–antagonist myoneural direct myoelectric control (15, 16). To compensate for these interfaces (AMIs), which surgically preserve and couple agonist– shortcomings, considerable effort has been spent on developing antagonist muscle pairs for the subtalar and ankle joints. AMIs are and deploying pattern-recognition–based myoelectric control designed to restore physiological neuromuscular dynamics, enable strategies (17–19). However, even with these advanced myo- bidirectional neural signaling, and offer greater neuroprosthetic electric devices and controllers, end users find their operation controllability compared to traditional amputation techniques.
    [Show full text]
  • How Does Psychological Trauma Affect the Body and the Brain the Cortex the Limbic System
    How Does Psychological Trauma Affect the Body and the Brain It would take many volumes to thoroughly discuss the brain in total. In this book I will stick to an overview discussion of the parts of the brain that are most relevant to the essential understanding of trauma: the cortex (the thinking center of the brain) and the Iimbic system (the emotional and survival center of the brain). The Cortex Among other functions, the cortex is the site of conscious thought and awareness. Maintaining attention to our external environment (what we see, hear, smell, etc.) as well as our internal environment (thoughts, body sensations, and emotions) requires activity in the cortex. Thinking, including the recall of facts, description of procedures, recognition of time, understanding, and so on, also takes place in the cortex. Though it varies from individual to individual, low levels of increased stress with the accompanying increase in adrenaline levels will actually improve awareness, clear thinking, and memory.1 That is why coffee is such a popular beverage at work and among university students: a jolt of caffeine makes our memory, observations, and thinking processes sharper. However, past a certain (individually determined) level, increased adrenaline will degrade, that is, have the opposite effect on, those same processes. A most recognizable example is seen on television quiz programs. More often than not, contestants eliminated by a wrong answer will assert that when watching the program at home, they never missed an answer. Why then were they stumped when on TV? Most likely, their stress levels rose beyond the helpful low-adrenaline kick and succumbed to overload that dampened their ability to access information that was easily available under calmer circumstances.
    [Show full text]
  • Technische Universität München
    TECHNISCHE UNIVERSITÄT MÜNCHEN Lehrstuhl für Entwicklungsgenetik Molecular mechanisms that govern the establishment of sensory-motor networks Rosa-Eva Hüttl Vollständiger Abdruck der von der Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. E. Grill Prüfer der Dissertation: 1. Univ.-Prof. Dr. W. Wurst 2. Univ.-Prof. Dr. H. Luksch Die Dissertation wurde am 08.12.2011 bei der Technischen Universität München eingereicht und durch die Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt am 27.02.2012 angenommen. Erklärung Hiermit erkläre ich an Eides statt, dass ich die der Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt der Technischen Universität München zur Promotionsprüfung vorgelegte Arbeit mit dem Titel „Molecular mechanisms that govern the establishment of sensory-motor networks“ am Lehrstuhl für Entwicklungsgenetik unter der Anleitung und Betreuung durch Univ.-Prof. Dr. Wolfgang Wurst ohne sonstige Hilfe erstellt und bei der Abfassung nur die gemäß § 6 Abs. 5 angegebenen Hilfsmittel benutzt habe. Ich habe keine Organisation eingeschaltet, die gegen Entgelt Betreuerinnen und Betreuer für die Anfertigung von Dissertationen sucht, oder die mir obliegenden Pflichten hinsichtlich der Prüfungsleistung für mich ganz oder teilweise erledigt. Ich habe die Dissertation in dieser oder
    [Show full text]
  • Sensory History Matters for Visual Representation: Implications for Autism
    University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2015 Sensory History Matters for Visual Representation: Implications for Autism David Alexander Kahn University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Cognitive Psychology Commons, and the Neuroscience and Neurobiology Commons Recommended Citation Kahn, David Alexander, "Sensory History Matters for Visual Representation: Implications for Autism" (2015). Publicly Accessible Penn Dissertations. 1071. https://repository.upenn.edu/edissertations/1071 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/1071 For more information, please contact [email protected]. Sensory History Matters for Visual Representation: Implications for Autism Abstract How does the brain represent the enormous variety of the visual world? An approach to this question recognizes the types of information that visual representations maintain. The work in this thesis begins by investigating the neural correlates of perceptual similarity & distinctiveness, using EEG measurements of the evoked response to faces. In considering our results, we recognized that the effects being measured shared intrinsic relationships, both in measurement and in their theoretic basis. Using carry- over fMRI designs, we explored this relationship, ultimately demonstrating a new perspective on stimulus relationships based around sensory history that best explains the modulation of brain responses being measured. The result of this collection of experiments is a unified model of neural response modulation based around the integration of recent sensory history into a continually-updated reference; a "drifting- norm." With this novel framework for understanding neural dynamics, we tested whether cognitive theories of autism spectrum disorder (ASD) might have a foundation in altered neural coding for perceptual information.
    [Show full text]
  • Phillips 2012 an Examination of the Efficacy of Sensory Integration in Occupational Therapy.Pdf
    A Senior Honors Thesis February 2012 An Examination of the Efficacy of Sensory Integration in Occupational Therapy Shannon Phillips If an individual with sensory processing disorder undergoes occupational therapy treatment with the incorporation of sensory integration techniques, he or she will show measurable improvements in overall functioning, i.e., tactile sensitivity, taste/smell sensitivity, movement sensitivity, seeking sensation or under-responsiveness, and visual/auditory sensitivity. ACKNOWLEDGMENTS I would like to thank and acknowledge the many people who have helped make this Thesis of An Examination of the Efficacy of Sensory Integration in Occupational Therapy a success. First of all, to my advisor Mrs. Betty Marko, thank you for all the time spent with me in meetings, reading and revising my project, and giving me such wonderful guidance, advice, and insight. I very much appreciate all you have done and more. To my reader, Dr. Bob Humphries, thank you for your generous suggestions and for taking the time to help read and revise my project. To Dr. Laci Fiala Ades, thank you so much for all your help with my data consolidation. Without you as my statistical liaison, I would not have been able to convey my results in such an informative and intelligent manner. To Dr. Koop Berry and the rest of the Honors Committee, thank you for presenting me with this opportunity to come up with original research regarding my interest in occupational therapy. I know this experience can only help in my journey to graduate school, and it has left me with valuable lessons for life as well.
    [Show full text]
  • Sensory Processing Disorder with Strategies for Learning Behavior
    Sensory Processing Disorder with Strategies for learning Behavior and Social Skills Description: Understanding and learning to recognize the sensory needs of the children who have spectrum processing disorder. Bonnie Vos, MS, O.T.R./L History of Diagnosis Autism criterion Autism not it’s better defined, # Subtype own diagnostic of diagnosis s are category increased rapidly DSM I DSM II DSM II DSM DSM IV DSM V 1952 1968 1980 III-R 1992 2013 1987 Autism not it’s Autism New subtypes are own diagnostic becomes its added, now 16 category own diagnostic behaviors are category characteristic (must have 6 to qualify) History of Diagnosis 1. New name (Autism Spectrum Disorder) 2. One diagnosis-no subcategories 3. Now 2 domains (social and repetitive) 4. Symptom list is consolidated 5. Severity rating added 6. Co-morbid diagnosis is now permitted 7. Age onset criterion removed 8. New diagnosis: Social (pragmatic) Communication disorder What is Autism • http://www.parents.com/health/autism/histo ry-of-autism/ Coding of the brain • One theory of how the brain codes is using a library metaphor. • Books=experiences • Subjects areas are representations of the main neuro- cognitive domains: • The subjects are divided into 3 sections: 1. Sensory: visual, auditory, ect. 2. Integrated skills: motor planning (praxis), language 3. Abilities: social and cognitive • Designed as a model for ideal development The Brain Library • Each new experience creates a book associated with the subject area that are active during the experience • Books are symbolic of whole or parts of experiences • The librarian in our brain – Analyzes – Organizes – Stores – Retrieves Brain Library • The earliest experiences or sensory inputs begin writing the books that will eventually fill the foundational sections of our brain Libraries – Sensory integration begins in-utero – Example: vestibular=14 weeks in-utero – Example: Auditory=20 weeks in-utero Brain Library 1.
    [Show full text]
  • The Neural Dynamics of Perceptual Adaptation to Degraded Speech
    Julia Erb: The neural dynamics of perceptual adaptation to degraded speech. Leipzig: Max Planck Institute for Human Cognitive and Brain Sciences, 2014 (MPI Series in Human Cognitive and Brain Sciences; 159) The neural dynamics of perceptual adaptation to degraded speech Impressum Max Planck Institute for Human Cognitive and Brain Sciences, 2014 Diese Arbeit ist unter folgender Creative Commons-Lizenz lizenziert: http://creativecommons.org/licenses/by-nc/3.0 Druck: Sächsisches Druck- und Verlagshaus Direct World, Dresden Titelbild: © Moritz Ellerich / RaumZeitPiraten / Fabelphonetikum (rhizome schematic) 2014 ISBN 978-3-941504-43-1 The neural dynamics of perceptual adaptation to degraded speech Der Fakultät für Biowissenschaften, Pharmazie und Psychologie der Universität Leipzig eingereichte D I S S E R T A T I O N zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) vorgelegt von Julia Erb, M.Sc. (Neuroscience) geboren am 17. September 1985 in Heilbronn Leipzig, den 14. Februar 2014 Acknowledgements I would like to thank several people who supported me and decisively contributed to my work during the last three years at the Max Planck Institute. First, I cordially thank my supervisor Jonas Obleser. Jonas was incredibly supportive in all stages of this thesis, during the conception, analysis and the publication of the experiments. Thank you for your generous encouragement to my development as a scientist. I am obliged to Erich Schröger and Mark Eckert who agreed to assess my work. I thank my colleagues and friends from the Auditory Cognition group, Björn Herrmann, Sung-Joo Lim, Mathias Scharinger, Antje Strauß, Anna Wilsch and Malte Wöstmann, for fruitful discussions in Tuesday morning group meetings and Friday evening Cantona sessions – I miss them.
    [Show full text]
  • Nociceptor Sensory Neuron–Immune Interactions in Pain and Inflammation
    Feature Review Nociceptor Sensory Neuron–Immune Interactions in Pain and Inflammation 1,2 2 Felipe A. Pinho-Ribeiro, Waldiceu A. Verri Jr., and 1, Isaac M. Chiu * Nociceptor sensory neurons protect organisms from danger by eliciting pain Trends and driving avoidance. Pain also accompanies many types of inflammation and A bidirectional crosstalk between noci- injury. It is increasingly clear that active crosstalk occurs between nociceptor ceptor sensory neurons and immune cells actively regulates pain and neurons and the immune system to regulate pain, host defense, and inflamma- inflammation. tory diseases. Immune cells at peripheral nerve terminals and within the spinal cord release mediators that modulate mechanical and thermal sensitivity. In Immune cells release lipids, cytokines, and growth factors that have a key role turn, nociceptor neurons release neuropeptides and neurotransmitters from in sensitizing nociceptor sensory neu- nerve terminals that regulate vascular, innate, and adaptive immune cell rons by acting in peripheral tissues and responses. Therefore, the dialog between nociceptor neurons and the immune the spinal cord to produce neuronal plasticity and chronic pain. system is a fundamental aspect of inflammation, both acute and chronic. A better understanding of these interactions could produce approaches to treat Nociceptor neurons release neuropep- chronic pain and inflammatory diseases. tides that drive changes in the vascu- lature, lymphatics, and polarization of innate and adaptive immune cell Neuronal Pathways of Pain Sensation function. Pain is one of four cardinal signs of inflammation defined by Celsus during the 1st century AD (De Nociceptor neurons modulate host Medicina). Nociceptors are a specialized subset of sensory neurons that mediate pain and defenses against bacterial and fungal densely innervate peripheral tissues, including the skin, joints, respiratory, and gastrointestinal pathogens, and, in some cases, neural fi tract.
    [Show full text]
  • Advances in Understanding Nociception and Neuropathic Pain
    J Neurol DOI 10.1007/s00415-017-8641-6 REVIEW Advances in understanding nociception and neuropathic pain Ewan St. John Smith1 Received: 14 July 2017 / Revised: 2 October 2017 / Accepted: 3 October 2017 © The Author(s) 2017. This article is an open access publication Abstract Pain results from the activation of a subset of is considered unlikely in C. elegans, but the case for cer- sensory neurones termed nociceptors and has evolved as a tain organisms, especially fsh, is more contentious [2–4]. “detect and protect” mechanism. However, lesion or dis- Numerous reviews have been written about diferent aspects ease in the sensory system can result in neuropathic pain, of pain, from its molecular basis [5–10] and genetic mecha- which serves no protective function. Understanding how nisms [11–13] to its pharmacological treatment [14–16]. the sensory nervous system works and what changes occur The purpose of this review is to discuss how recent insights in neuropathic pain are vital in identifying new therapeu- into pain mechanisms from pre-clinical research may lead tic targets and developing novel analgesics. In recent years, to breakthroughs in our understanding, and hopefully treat- technologies such as optogenetics and RNA-sequencing have ment, of chronic pain. been developed, which alongside the more traditional use of Chronic pain is usually defned as regularly occurring animal neuropathic pain models and insights from genetic pain over a period of several months and it has a prevalence variations in humans have enabled signifcant advances to be of ~11–19% of the adult population [17–19]. Broadly speak- made in the mechanistic understanding of neuropathic pain.
    [Show full text]
  • The Cookie Crumbles: a Case of Sensory Sleuthing. Brainlink: Sensory Signals. INSTITUTION Baylor Coll
    DOCUMENT RESUME ED 448 044 SE 064 337 AUTHOR Boyle, Grace TITLE The Cookie Crumbles: A Case of Sensory Sleuthing. BrainLink: Sensory Signals. INSTITUTION Baylor Coll. of Medicine, Houston, TX. SPONS AGENCY National Institutes of Health (DHHS), Bethesda, MD. ISBN ISBN-1-888997-19-2 PUB DATE 1997-00-00 NOTE 169p.; Illustrated by T. Lewis. Revised by Judith Dresden and Barbara Tharp. Science notations by Nancy Moreno. For other books in the BrainLink series, see SE 064 335-338. CONTRACT R25-RR13454 PUB TYPE Guides Classroom Teacher (052) EDRS PRICE MF01/PC07 Plus Postage. DESCRIPTORS Biology; *Brain; Content Area Reading; Elementary Education; Human Body; Mathematics Education; *Neurology; Problem Solving; *Science Activities; *Science Instruction ABSTRACT The BrainLink project offers educational materials focusing on current neuroscience issues with the goal of promoting a deeper understanding of how the nervous system works and why the brain makes each individual special while conveying the excitement of "doing science" among upper elementary and middle school students. Project materials engage students and their families in neuroscience issues as they learn fundamental physical and neuroscience concepts and acquire problem-solving and decision making skills. Each BrainLink unit targets a major neuroscience topic and consists of a colorful science Adventures storybook, a comprehensive Teacher's Guide to hands-on activities in science and mathematics, a Reading Link language arts supplement, and a fun and informative Explorations mini-magazine for students to use with their families at home or in the classroom. This issue offers a unique approach to learning how the senses work, including visual illusions and how the brain processes sensory information.(ASK) Reproductions supplied by EDRS are the best that can be made from the original document.
    [Show full text]
  • Neural Mechanisms of Actions of Transcranial Electrical Stimulation
    Neural Mechanisms of Actions of Transcranial Electrical Stimulation By Kohitij Kar A Dissertation submitted to the Graduate School-Newark Rutgers, The State University of New Jersey in partial fulfillment of the requirements for the degree of Doctor of Philosophy Graduate Program in Behavioral and Neural Sciences written under the direction of Bart Krekelberg and approved by ________________________ ________________________ ________________________ ________________________ ________________________ Newark, New Jersey January 2015 ©2014 Kohitij Kar ALL RIGHTS RESERVED Abstract of the Dissertation Neural Mechanisms of Actions of Transcranial Electrical Stimulation By Kohitij Kar Dissertation Director: Bart Krekelberg There is considerable evidence for clinical and behavioral efficacy of transcranial electrical stimulation (tES). The effects range from suppressing Parkinsonian tremors to augmenting human learning and memory. Despite widespread use, the neurobiological mechanisms of action of tES on the intact human brain are unclear. In the work presented in this thesis, I have taken a multi-methodological approach to probe tES mechanisms. First, I studied the electric field spread induced by the application of tES, behaviorally. Second, I examined the behavioral effects of tES on human motion perception. I observed that tES (10 Hz, 0.5 mA) applied over area hMT+ (a brain area specialized in processing visual motion) attenuates motion adaptation. This result led to the hypothesis that tES-induced membrane voltage modulations reduce adaptation in motion-selective neurons. Finally, I tested this hypothesis by directly measuring tES-induced neural activity changes in a homologous area in the macaque brain (area MT). Tuning curve estimates of macaque MT neurons showed that tES attenuated the effects of visual motion adaptation on tuning amplitude and width.
    [Show full text]
  • Division of Physiology
    PHYSIOLOGY EXAMINATION SYLLABUS Theoretical exam 1. Cell membranes. Transport of substances through cell membranes. 2. Membrane potentials. Resting membrane potential of nerves. 3. Nerve action potential. Propagation of the action potential. Rhythmicity. 4. Signal transmission in nerve fibers. Excitation - the process of eliciting the action potential. Threshold for excitation, refractory period. Inhibition of excitability. 5. Organization and functions of the nervous system. Sensory and motor parts, integrative function. Major levels of central nervous system function. The neuron. 6. Synapses. Types of synapses. Structure of the synapse. Characteristics of transmission in chemical synapses. 7. Membrane receptors. Synaptic transmitters. 8. Postsynaptic potentials - types. Generation of action potentials in the axon. Neuronal inhibition - types. Neuroglia. 9. Time course of postsynaptic potentials. Spatial and temporal summation. "Facilitation" of neurons. Functions of dendrites for exciting neurons. Fatigue of synaptic transmission. Effect of drugs. 10. Transmission and processing of signals in neuronal pools. Neuronal circuits - convergence, divergence, reverberating circuits, inhibitory circuits. 11. Reflexes - definition, types. Reflex arch. Classification of reflexes. Spinal reflexes. 12. General organization of the autonomic nervous system. Characteristics of sympathetic and parasympathetic function - transmitters, receptors. 13. Sympathetic and parasympathetic tone. Denervation effects. Autonomic reflexes. Function of the adrenal medullae. 14. Effects of autonomic nervous system on specific organs. "Stress" response of the sympathetic nervous system. Control of the autonomic nervous system. 15. Physiologic anatomy of skeletal muscle. General and molecular mechanism of muscle contraction. 16. Energetics of muscle contraction. Characteristics of whole muscle contraction. 17. The neuromuscular junction. Excitation-contraction coupling. 18. Characteristics of smooth muscle. Excitation and contraction of smooth muscle. 19.
    [Show full text]