NEUROSCIENCE Edited by DALE PURVES GEORGE J. AUGUSTINE DAVID FITZPATRICK WILLIAM C. HALL ANTHONY-SAMUEL LAMANTIA JAMES O. MCNAMARA S MARK WILLIAMS Sinauer associates, Inc. Publishers Sunderland, Massachusetts U.S.A
Edited by DALE PURVES GEORGE J. AUGUSTINE DAVID FITZPATRICK WILLIAM C. HALL ANTHONY-SAMUEL LAMANTIA JAMES O. MCNAMARA S. MARK WILLIAMS NEUROSCIENCE THIRD EDITION Sinauer Associates, Inc. • Publishers Sunderland, Massachusetts U.S.A. Purves3/eFM 5/13/04 12:59 PM Page iii
THE COVER Dorsal view of the human brain Courtesy of S. Mark Williams Neuroscience NEUROSCIENCE: Third Edition Copyright C 2004 by Sinauer Associates, Inc. All rights reserved This book may not be reproduced in whole or in part without permission. Address inquiries and orders to Sinauer Associates, Inc. 23 Plumtree road Sunderland, MA 01375 U.S.A vww. sinauer. com FAX:413-549-1118 orders@sinauer.com publish@sinauer.com Library of Congress Cataloging-in-Publication Data Neuroscience / edited by Dale Purves [et al. ].-3rd ed Includes bibliographical references and index ISBN 0-87893-725-0(casebound alk paper) 1. Neurosciences DNLM: 1. Nervous System Physiology. 2. Neurochemistry WL 102 N50588 2004 I Purves, Dale QP355.2N4872004 6128-dc22 2004003973 Printed in U.S.A 54321
NEUROSCIENCE: Third Edition Copyright © 2004 by Sinauer Associates, Inc. All rights reserved. This book may not be reproduced in whole or in part without permission. Address inquiries and orders to Sinauer Associates, Inc. 23 Plumtree Road Sunderland, MA 01375 U.S.A. www.sinauer.com FAX: 413-549-1118 orders@sinauer.com publish@sinauer.com Library of Congress Cataloging-in-Publication Data Neuroscience / edited by Dale Purves ... [et al.].— 3rd ed. p. ; cm. Includes bibliographical references and index. ISBN 0-87893-725-0 (casebound : alk. paper) 1. Neurosciences. [DNLM: 1. Nervous System Physiology. 2. Neurochemistry. WL 102 N50588 2004] I. Purves, Dale. QP355.2.N487 2004 612.8—dc22 2004003973 Printed in U.S.A. 5 4 3 2 1 THE COVER Dorsal view of the human brain. (Courtesy of S. Mark Williams.) Purves3/eFM 5/13/04 12:59 PM Page iv
Contributo George J. Augustine, Ph. D Dona M. Chikaraishi, Ph Michael d. ehlers, M. D. Ph.D Gillian einstein ph D David Fitzpatrick, ph D William C. Hall, ph. D Erich Jarvis, Ph. Lawrence C. Katz, Ph D Julie Kauer, Ph. D Anthony-Samuel LaMantia, Ph D ames O. McNamara, MD Richard D. Mooney, Ph D Miguel A. L Nicolelis, M. D, Ph D Dale Purves, M.D Peter H. Reinhart. Ph. D Sidney A. Simon, Ph. D J H. Pate Skene, Ph D ames Voyvodic, ph. D Leonard E White. Ph. D S Mark Williams, Ph. D UNIT EDITORS UNIT I: George J. Augustine UNIT I: David Fitzp UNIT III: William C UNIT IV: Anthony-Samuel LaMantia UNIT V: Dale purves
George J. Augustine, Ph.D. Dona M. Chikaraishi, Ph.D. Michael D. Ehlers, M.D., Ph.D. Gillian Einstein, Ph.D. David Fitzpatrick, Ph.D. William C. Hall, Ph.D. Erich Jarvis, Ph.D. Lawrence C. Katz, Ph.D. Julie Kauer, Ph.D. Anthony-Samuel LaMantia, Ph.D. James O. McNamara, M.D. Richard D. Mooney, Ph.D. Miguel A. L. Nicolelis, M.D., Ph.D. Dale Purves, M.D. Peter H. Reinhart, Ph.D. Sidney A. Simon, Ph.D. J. H. Pate Skene, Ph.D. James Voyvodic, Ph.D. Leonard E. White, Ph.D. S. Mark Williams, Ph.D. UNIT EDITORS UNIT I: George J. Augustine UNIT II: David Fitzpatrick UNIT III: William C. Hall UNIT IV: Anthony-Samuel LaMantia UNIT V: Dale Purves Contributors Purves3/eFM 5/13/04 12:59 PM Page v
Contents in brief 1. Studying the Nervous Systems of Humans and Other Animals UNIT NEURAL SIGNALING 2. Electrical Signals of Nerve Cells 31 3. Voltage-Dependent Membrane Permeability 4 4 Channels and Transporters 69 5. Synaptic Transmission 93 6. Neurotransmitters, Receptors, and Their Effects 129 7. Molecular Signaling within Neurons 165 UNIT/ SENSATION AND SENSORY PROCESSING 8. The Somatic Sensory System 189 ain 10. Vision: The Eye 229 11. Central Visual Pathways 259 12. The Auditory System 283 13. The Vestibular System 315 14. The Chemical Senses 337 UNIT I MOVEMENT AND /TS CENTRAL CONTROL 15. Lower Motor Neuron Circuits and motor Control 371 16. Upper Motor Neuron Control of the Brainstem and Spinal Cord 393 17. Modulation of Movement by the Basal Ganglia 417 18 Modulation of Movement by the Cerebellum 435 19. Eye Movements and Sensory Motor Integration 453 20. The Visceral Motor System 469 UNIT/V THE CHANGING BRAIN 21. Early Brain Development 501 22. Construction of Neural Circuits 521 23. Modification of Brain Circuits as a Result of Experience 557 24. Plasticity of Mature Synapses and Circuits 575 UNITV COMPLEX BRAIN FUNCTIONS 25. The Association Cortices 613 26. Language and Speech 637 27. Sleep and Wakefulness 659 28. Emotions 687 29. Sex, Sexuality, and the Brain 711 30. Memory 733 APPENDIX A THE BRAINSTEM AND CRANIAL NERVES 755 APPENDIX B VASCULAR SUPPLY, THE MENINGES, AND THE VENTRICULAR SYSTEM 763
1. Studying the Nervous Systems of Humans and Other Animals 1 UNIT I NEURAL SIGNALING 2. Electrical Signals of Nerve Cells 31 3. Voltage-Dependent Membrane Permeability 47 4. Channels and Transporters 69 5. Synaptic Transmission 93 6. Neurotransmitters, Receptors, and Their Effects 129 7. Molecular Signaling within Neurons 165 UNIT II SENSATION AND SENSORY PROCESSING 8. The Somatic Sensory System 189 9. Pain 209 10. Vision: The Eye 229 11. Central Visual Pathways 259 12. The Auditory System 283 13. The Vestibular System 315 14. The Chemical Senses 337 UNIT III MOVEMENT AND ITS CENTRAL CONTROL 15. Lower Motor Neuron Circuits and Motor Control 371 16. Upper Motor Neuron Control of the Brainstem and Spinal Cord 393 17. Modulation of Movement by the Basal Ganglia 417 18. Modulation of Movement by the Cerebellum 435 19. Eye Movements and Sensory Motor Integration 453 20. The Visceral Motor System 469 UNIT IV THE CHANGING BRAIN 21. Early Brain Development 501 22. Construction of Neural Circuits 521 23. Modification of Brain Circuits as a Result of Experience 557 24. Plasticity of Mature Synapses and Circuits 575 UNIT V COMPLEX BRAIN FUNCTIONS 25. The Association Cortices 613 26. Language and Speech 637 27. Sleep and Wakefulness 659 28. Emotions 687 29. Sex, Sexuality, and the Brain 711 30. Memory 733 APPENDIX A THE BRAINSTEM AND CRANIAL NERVES 755 APPENDIX B VASCULAR SUPPLY, THE MENINGES, AND THE VENTRICULAR SYSTEM 763 Contents in Brief Purves3/eFM 5/13/04 12:59 PM Page vii
Contents Preface xvi Acknowledgments xvii Supplements to Accompany NEUROSCIENCe xviii Chapter 1 Studying the Nervous Systems of humans and other Animals 1 ervie Overall Organization of the Human Nervous Genetics, Genomics, and the brain 1 The Cellular Components of the Nervous System 2 Neuroanatomical Terminology 16 Neurons 4 The Subdivisions of the Central Nervous System 18 Neuroglial Cells 8 Organizational Principles of Neural Systems 20 Cellular Diversity in the Nervous System 9 Functional Analysis of Neural Systems 2 Neural Circuits 1 Analyzing Complex Behavior 24 Box A Brain Imaging Techniq Unit NEURAL SIGNALING Chapter 2 Electrical Signals Chapter 3 Voltage-Dependent Membrane of Nerve Cells 31 Permeability 47 Overview 31 Overview 47 Electrical Potentials across Nerve Cell Membranes 31 Ionic Currents Across Nerve Cell Membranes 4 How Ionic Movements Produce Electrical Signals 34 Box A The Voltage Clamp Method 48 The Forces That Create Membrane Potentials 36 Two Types of Voltage-Dependent Ionic Current 49 Electrochemical Equilibrium in an Environment with Two Voltage-Dependent Membrane Conductances 52 More Than one permeant ion 38 Reconstruction of the Action Potential 54 The lonic Basis of the Resting Membrane Potential 40 Long-Distance Signaling by Means of Action Box A The remarkable giant Nerve cells Potentials 56 of Squid Box B Threshold 57 The Ionic Basis of Action Potentials 43 Box C Passive Membrane Properties 60 Box B Action potential form The Refractory Period 61 and Nomenclature 44 ncreased Conduction Velocity as a Result Summary 45 of Myelination 63 Summary 65 Box D Multiple Sclerosis 66
Chapter 1 Studying the Nervous Systems of Humans and Other Animals 1 Overview 1 Genetics, Genomics, and the Brain 1 The Cellular Components of the Nervous System 2 Neurons 4 Neuroglial Cells 8 Cellular Diversity in the Nervous System 9 Neural Circuits 11 Overall Organization of the Human Nervous System 14 Neuroanatomical Terminology 16 The Subdivisions of the Central Nervous System 18 Organizational Principles of Neural Systems 20 Functional Analysis of Neural Systems 23 Analyzing Complex Behavior 24 BOX A Brain Imaging Techniques 25 Summary 26 Contents Unit I NEURAL SIGNALING Chapter 2 Electrical Signals of Nerve Cells 31 Overview 31 Electrical Potentials across Nerve Cell Membranes 31 How Ionic Movements Produce Electrical Signals 34 The Forces That Create Membrane Potentials 36 Electrochemical Equilibrium in an Environment with More Than One Permeant Ion 38 The Ionic Basis of the Resting Membrane Potential 40 BOX A The Remarkable Giant Nerve Cells of Squid 41 The Ionic Basis of Action Potentials 43 BOX B Action Potential Form and Nomenclature 44 Summary 45 Chapter 3 Voltage-Dependent Membrane Permeability 47 Overview 47 Ionic Currents Across Nerve Cell Membranes 47 BOX A The Voltage Clamp Method 48 Two Types of Voltage-Dependent Ionic Current 49 Two Voltage-Dependent Membrane Conductances 52 Reconstruction of the Action Potential 54 Long-Distance Signaling by Means of Action Potentials 56 BOX B Threshold 57 BOX C Passive Membrane Properties 60 The Refractory Period 61 Increased Conduction Velocity as a Result of Myelination 63 Summary 65 BOX D Multiple Sclerosis 66 Preface xvi Acknowledgments xvii Supplements to Accompany NEUROSCIENCE xviii Purves3/eFM 5/13/04 12:59 PM Page viii
Chapter 4 Channels and Transporters 69 Chapter 6 Neurotransmitters and Their Overview Receptors 129 Ion Channels Underlying Action Potentials 69 Overview 129 Box A The Patch Clamp Method 70 Categories of Neurotransmitters 129 The Diversity of Ion Channels 73 Acetylcholine 129 Box B Expression of lon Channels in Xenopus Box A Addiction 134 Oocytes 75 Box B Neurotoxins that Act on Postsynaptic Voltage-Gated Ion Channels 36 Ligand-Gated Ion Channels 78 Glutamate 137 Stretch- and Heat-Activated Channels 78 Box C Myasthenia Gravis: An Autoimmune The Molecular Structure of Ion Channels 79 Disease of Neuromuscular Synapses 1 Box C Toxins That Poison lon Channels GABA and Glycine 143 Box D Diseases Caused by Altered lon Box D Excitotoxicity Following Acute Brain Channels 84 Injury 145 Active Transporters Create and Maintain Ion The Biogenic Amines 14 Gradients 86 Functional Properties of the Na*/K+ Pump 87 Box E Biogenic Amine Neurotransmitters and The Molecular Structure of the Na/K Pump 89 Psychiatric Disorders 148 Summary 90 ATP and Other Purines 152 Peptide Neurotransmitters 153 Chapter 5 Synaptic Transmission 93 Unconventional Neurotransmitters 157 Overview 93 Box F Marijuana and the Brain 160 Electrical Synapses Summary 161 Signal Transmission at Chemical Synapses 96 Properties of Neurotransmitters 96 Chapter 7 Molecular Signaling within Box A Criteria that define a Neurons 165 Neurotransmitter 99 Overview 165 Quantal Release of Neurotransmitters 102 Strategies of Molecular Signaling 16 Release of Transmitters from Synaptic Vesicles 103 The Activation of Signaling Pathways 167 Local Recycling of Synaptic Vesicles 105 Receptor Types 16 The Role of Calcium in Transmitter Secretion 107 G-Proteins and Their Molecular Targets 170 Box B Diseases That Affect the Presynaptic Second Messengers 172 Terminal 108 Second Messenger Targets: Protein Kinases and Molecular Mechanisms of Transmitter Secretion 110 Phosphatases 175 Neurotransmitter Receptors 113 Nuclear Signaling 178 Box C Toxins that Affect transmitter Release 115 Examples of Neuronal Signal Transduction 181 Summary 184 Postsynaptic Membrane Permeability Changes during Synaptic Transmission 116 Excitatory and Inhibitory Postsynaptic Potentials 121 Summation of Synaptic Potentials 123 Two Families of Postsynaptic Receptors
Chapter 4 Channels and Transporters 69 Overview 69 Ion Channels Underlying Action Potentials 69 BOX A The Patch Clamp Method 70 The Diversity of Ion Channels 73 BOX B Expression of Ion Channels in Xenopus Oocytes 75 Voltage-Gated Ion Channels 76 Ligand-Gated Ion Channels 78 Stretch- and Heat-Activated Channels 78 The Molecular Structure of Ion Channels 79 BOX C Toxins That Poison Ion Channels 82 BOX D Diseases Caused by Altered Ion Channels 84 Active Transporters Create and Maintain Ion Gradients 86 Functional Properties of the Na+/K+ Pump 87 The Molecular Structure of the Na+/K+ Pump 89 Summary 90 Chapter 5 Synaptic Transmission 93 Overview 93 Electrical Synapses 93 Signal Transmission at Chemical Synapses 96 Properties of Neurotransmitters 96 BOX A Criteria That Define a Neurotransmitter 99 Quantal Release of Neurotransmitters 102 Release of Transmitters from Synaptic Vesicles 103 Local Recycling of Synaptic Vesicles 105 The Role of Calcium in Transmitter Secretion 107 BOX B Diseases That Affect the Presynaptic Terminal 108 Molecular Mechanisms of Transmitter Secretion 110 Neurotransmitter Receptors 113 BOX C Toxins That Affect Transmitter Release 115 Postsynaptic Membrane Permeability Changes during Synaptic Transmission 116 Excitatory and Inhibitory Postsynaptic Potentials 121 Summation of Synaptic Potentials 123 Two Families of Postsynaptic Receptors 124 Summary 126 Chapter 6 Neurotransmitters and Their Receptors 129 Overview 129 Categories of Neurotransmitters 129 Acetylcholine 129 BOX A Addiction 134 BOX B Neurotoxins that Act on Postsynaptic Receptors 136 Glutamate 137 BOX C Myasthenia Gravis: An Autoimmune Disease of Neuromuscular Synapses 140 GABA and Glycine 143 BOX D Excitotoxicity Following Acute Brain Injury 145 The Biogenic Amines 147 BOX E Biogenic Amine Neurotransmitters and Psychiatric Disorders 148 ATP and Other Purines 152 Peptide Neurotransmitters 153 Unconventional Neurotransmitters 157 BOX F Marijuana and the Brain 160 Summary 161 Chapter 7 Molecular Signaling within Neurons 165 Overview 165 Strategies of Molecular Signaling 165 The Activation of Signaling Pathways 167 Receptor Types 168 G-Proteins and Their Molecular Targets 170 Second Messengers 172 Second Messenger Targets: Protein Kinases and Phosphatases 175 Nuclear Signaling 178 Examples of Neuronal Signal Transduction 181 Summary 184 Contents ix Purves3/eFM 5/13/04 12:59 PM Page ix
x Contents Unit/ SENSATION AND SENSORY PROCESSING Chapter 8 The Somatic Sensory System 189 Chapter 10 Vision: The Eye 229 Overy Overview 229 Cutaneous and Subcutaneous Somatic Sensory atomy of the Ey Receptors 185 The Formation of Images on the Retina 2: mechanoreceptors Specialized to Receive Tactile Box A Myopia and Other Refractive Errors 232 Inform The Retina 234 Differences in Mechanosensory Discrimination across Phototransduction 236 the body Surface 193 Box A Receptive Fields and Sensory Maps Box b Retinitis pic gmentosa 23 in the Cricket 195 Functional Specialization of the Rod and Cone Box B Dynamic Aspects of Somatic Sensory Systems 240 Receptive Fields 196 Box C Macular Degeneration 243 Anatomical Distribution of rods and Cones 244 Mechanoreceptors Specialized for Proprioception 197 Active Tactile Exploration 199 Cones and Color Vision 245 The Major Afferent Pathway for Mechanosensory Box D The Importance of Context in Color Information: The Dorsal Column-Medial Lemniscus Perception 247 System 199 Retinal Circuits for Detecting Luminance The Trigeminal Portion of the Mechanosensory Change 249 System 202 Box E The Perception of Light Intensity 250 Box C Dermatomes 202 Contribution of Retinal Circuits to light The Somatic Sensory Components of the Thalamus 203 Adaptatio he Somatic Sensory Cortex 203 Summary 257 Higher-Order Cortical Representations 206 BOx D Patterns of Organization within the Chapter 11 Central Visual Pathways 259 Sensory Cortices: Brain Modules 207 Summary 208 Central Projections of Retinal Ganglion Cells 259 Box A The Blind Spot 262 Chapter 9 Pain 209 The Retinotopic Representation of the Visual Field 263 Overview 209 Visual field Deficits 267 Nociceptors 209 The Functional Organization of the Striate Cortex 269 Transduction of nociceptive Signals 211 The Columnar Organization of the Striate Cortex 271 Box A Capsaicin 212 Box B Random Dot Stereograms and Related Central Pain Pathways 213 Amusements 272 Box B Referred Pain 215 Division of Labor within the Primary Visual Box C A Dorsal Column Pathway for Visceral Pathway 275 Pain 218 Box C Optical Imaging of Functional Domains in the visual Cortex 276 Sensitization 220 Box D Phantom limbs and phantom pain 22 The Functional Organization of Extrastriate Visua Areas 278 Descending Control of Pain Perception 224 Summary 281 The Placebo Effect 224 The Physiological Basis of Pain Modulation 225 Chapter 12 The Auditory System 283 umma ry227 Overview 283 Sound 283 The Audible Spectrum 284
x Contents Chapter 8 The Somatic Sensory System 189 Overview 189 Cutaneous and Subcutaneous Somatic Sensory Receptors 189 Mechanoreceptors Specialized to Receive Tactile Information 192 Differences in Mechanosensory Discrimination across the Body Surface 193 BOX A Receptive Fields and Sensory Maps in the Cricket 195 BOX B Dynamic Aspects of Somatic Sensory Receptive Fields 196 Mechanoreceptors Specialized for Proprioception 197 Active Tactile Exploration 199 The Major Afferent Pathway for Mechanosensory Information: The Dorsal Column–Medial Lemniscus System 199 The Trigeminal Portion of the Mechanosensory System 202 BOX C Dermatomes 202 The Somatic Sensory Components of the Thalamus 203 The Somatic Sensory Cortex 203 Higher-Order Cortical Representations 206 BOX D Patterns of Organization within the Sensory Cortices: Brain Modules 207 Summary 208 Chapter 9 Pain 209 Overview 209 Nociceptors 209 Transduction of Nociceptive Signals 211 BOX A Capsaicin 212 Central Pain Pathways 213 BOX B Referred Pain 215 BOX C A Dorsal Column Pathway for Visceral Pain 218 Sensitization 220 BOX D Phantom Limbs and Phantom Pain 222 Descending Control of Pain Perception 224 The Placebo Effect 224 The Physiological Basis of Pain Modulation 225 Summary 227 Chapter 10 Vision: The Eye 229 Overview 229 Anatomy of the Eye 229 The Formation of Images on the Retina 231 BOX A Myopia and Other Refractive Errors 232 The Retina 234 Phototransduction 236 BOX B Retinitis Pigmentosa 239 Functional Specialization of the Rod and Cone Systems 240 BOX C Macular Degeneration 243 Anatomical Distribution of Rods and Cones 244 Cones and Color Vision 245 BOX D The Importance of Context in Color Perception 247 Retinal Circuits for Detecting Luminance Change 249 BOX E The Perception of Light Intensity 250 Contribution of Retinal Circuits to Light Adaptation 254 Summary 257 Chapter 11 Central Visual Pathways 259 Overview 259 Central Projections of Retinal Ganglion Cells 259 BOX A The Blind Spot 262 The Retinotopic Representation of the Visual Field 263 Visual Field Deficits 267 The Functional Organization of the Striate Cortex 269 The Columnar Organization of the Striate Cortex 271 BOX B Random Dot Stereograms and Related Amusements 272 Division of Labor within the Primary Visual Pathway 275 BOX C Optical Imaging of Functional Domains in the Visual Cortex 276 The Functional Organization of Extrastriate Visual Areas 278 Summary 281 Chapter 12 The Auditory System 283 Overview 283 Sound 283 The Audible Spectrum 284 Unit II SENSATION AND SENSORY PROCESSING Purves3/eFM 5/13/04 12:59 PM Page x
A Synopsis of Auditory Function 285 How Semicircular Canal Neurons Sense angular Box A Four Causes of Acquired Hearing Loss 285 Accelerations 325 Box B Music 286 Box C Throwing Cold Water on the Vestibular The External ear 287 System 326 The Middle ear 289 Central Pathways for Stabilizing Gaze, Head, and Posture 328 The Inner ear 289 Box C Sensorineural Hearing Loss and Cochlear Vestibular Pathways to the Thalamus and Cortex 331 Implants 290 BOx D Mauthner Cells in Fish 332 Box D The sweet sound of distortion 295 Summary 333 Hair Cells and the Mechanoelectrical Transduction of Sound waves 294 Chapter 14 The Chemical Senses 337 Two Kinds of Hair Cells in the Cochlea 300 Overview 337 Tuning and Timing in the Auditory Nerve 301 The Organization of the Olfactory System 337 How Information from the Cochlea Reaches Targets in Olfactory Perception in Humans 339 the brainstem 303 Physiological and Behavioral Responses to Integrating Information from the Two Ears 303 Odorants 341 Monaural Pathways from the Cochlear Nucleus to the The Olfactory Epithelium and Olfactory Receptor Lateral Lemniscus 307 Neurons 342 tegration in the Inferior Colliculus 307 BoX A Olfaction Pheromones, and behavior in The Auditory Thalamus 308 the hawk moth 344 The Auditory Cortex 309 The Transduction of Olfactory Signals 345 Box E Representing Complex Sounds in the Odorant Receptors 346 Brains of Bats and Humans 310 Olfactory Coding 348 Summary 31 Box B Temporal"Coding"of Olfactory Chapter 13 The Vestibular System 315 Information in Insects 350 Overview 315 Central Projections of the Olfactory Bulb 353 The Vestibular Labyrinth 315 The Organization of the Taste System 354 Taste Perception in Humans 356 Vestibular Hair Cells 316 The Otolith Organs: The Utricle and Saccule 317 Idiosyncratic Responses to Tastants 357 Box A A Primer on Vestibular Navigation 318 The Organization of the Peripheral Taste System 359 Box B Adaptation and Tuning of Vestibular Hair Taste Receptors and the Transduction of Taste Cells 320 Signals 360 How Otolith Neurons Sense Linear forces 322 Neural Coding in the Taste System 362 The semicircular Canals 324 Trigeminal Chemoreception 363 Summary 366 Unit/ MOVEMENT AND ITS CENTRAL CONTROL Chapter 15 Lower Motor Neuron Circuits Motor Neuron-Muscle Relationships 373 and motor Control 371 The Motor Unit 375 The Regulation of Muscle Force 377 Neural Centers responsible for Movement 371 The Spinal Cord Circuitry Underlying Muscle Stretch Reflexes 379
Chapter 15 Lower Motor Neuron Circuits and Motor Control 371 Overview 371 Neural Centers Responsible for Movement 371 Motor Neuron–Muscle Relationships 373 The Motor Unit 375 The Regulation of Muscle Force 377 The Spinal Cord Circuitry Underlying Muscle Stretch Reflexes 379 A Synopsis of Auditory Function 285 BOX A Four Causes of Acquired Hearing Loss 285 BOX B Music 286 The External Ear 287 The Middle Ear 289 The Inner Ear 289 BOX C Sensorineural Hearing Loss and Cochlear Implants 290 BOX D The Sweet Sound of Distortion 295 Hair Cells and the Mechanoelectrical Transduction of Sound Waves 294 Two Kinds of Hair Cells in the Cochlea 300 Tuning and Timing in the Auditory Nerve 301 How Information from the Cochlea Reaches Targets in the Brainstem 303 Integrating Information from the Two Ears 303 Monaural Pathways from the Cochlear Nucleus to the Lateral Lemniscus 307 Integration in the Inferior Colliculus 307 The Auditory Thalamus 308 The Auditory Cortex 309 BOX E Representing Complex Sounds in the Brains of Bats and Humans 310 Summary 313 Chapter 13 The Vestibular System 315 Overview 315 The Vestibular Labyrinth 315 Vestibular Hair Cells 316 The Otolith Organs: The Utricle and Saccule 317 BOX A A Primer on Vestibular Navigation 318 BOX B Adaptation and Tuning of Vestibular Hair Cells 320 How Otolith Neurons Sense Linear Forces 322 The Semicircular Canals 324 How Semicircular Canal Neurons Sense Angular Accelerations 325 BOX C Throwing Cold Water on the Vestibular System 326 Central Pathways for Stabilizing Gaze, Head, and Posture 328 Vestibular Pathways to the Thalamus and Cortex 331 BOX D Mauthner Cells in Fish 332 Summary 333 Chapter 14 The Chemical Senses 337 Overview 337 The Organization of the Olfactory System 337 Olfactory Perception in Humans 339 Physiological and Behavioral Responses to Odorants 341 The Olfactory Epithelium and Olfactory Receptor Neurons 342 BOX A Olfaction, Pheromones, and Behavior in the Hawk Moth 344 The Transduction of Olfactory Signals 345 Odorant Receptors 346 Olfactory Coding 348 The Olfactory Bulb 350 BOX B Temporal “Coding” of Olfactory Information in Insects 350 Central Projections of the Olfactory Bulb 353 The Organization of the Taste System 354 Taste Perception in Humans 356 Idiosyncratic Responses to Tastants 357 The Organization of the Peripheral Taste System 359 Taste Receptors and the Transduction of Taste Signals 360 Neural Coding in the Taste System 362 Trigeminal Chemoreception 363 Summary 366 Contents xi Unit III MOVEMENT AND ITS CENTRAL CONTROL Purves3/eFM 5/13/04 12:59 PM Page xi
xii Contents The Influence of Sensory activity on Motor Behavior Circuits within the Basal Ganglia System 424 Box A Huntingtons Disease 426 Other Sensory Feedback That Affects Motor Box B Parkinsons Disease: An Opportunity for Performance 382 Novel Therapeutic Approaches 429 Box A Locomotion in the Leech and the Lamprey Box C Basal Ganglia Loops and Non-Motor 384 Brain Functions 432 Flexion Reflex Pathways 387 ummah ry433 Spinal Cord Circuitry and Locomotion 387 Box B The Autonomy of Central Pattern Chapter 18 Modulation of Movement by Generators: Evidence from the lobster the Cerebellum 435 Stomatogastric Ganglion 388 The Lower Motor Neuron Syndrome 389 Box C Amyotrophic Lateral Sclerosis 391 Organization of the Cerebellum 435 Summary 391 Projections to the Cerebellum 438 Projections from the Cerebellum 440 Chapter 16 Upper Motor Neuron Control Circuits within the Cerebellum 441 of the brainstem and spinal BOX A Prion Diseases 444 Cord 393 Cerebellar Circuitry and the Coordination of Ongoing Overview 393 Movement 445 Descending Control of Spinal Cord Circuitry Futher Consequences of Cerebellar Lesions 448 General Information 393 Summary 449 Motor Control Centers in the Brainstem: Upper Motor Box B Genetic Analysis of Cerebellar Function 450 Neurons that maintain balance and posture 397 Box A The reticular Formation 398 Chapter 19 Eye Movements and Sensory The Corticospinal and Corticobulbar Pathways Motor Integration 453 Upper Motor Neurons That Initiate Complex Overview 453 Voluntary Movements 402 What Eye Movements Accomplish 453 Box B Descending Projections to Cranial Nerve The Actions and Innervation of Extraocular muscles Motor Nuclei and Their Importance in Diagnosing the Cause of Motor Deficits 404 Box A The Perception of Stabilized Retinal Functional Organization of the Primary Motor Cortex Types of Eye Movements and Their Functions Neural Control of Saccadic Eye Movements Box C What Do Motor Maps Represent?408 Box B Sensory Motor Integration in the The Premotor Cortex 411 Superior Colliculus 462 Box D Sensory Motor Talents and Cortical Neural Control of Smooth Pursuit Movements 466 410 Neural Control of Vergence Movements 466 Damage to Descending Motor Pathways: The Upper Motor neuro Box E Muscle Tone 414 Summary 415 Chapter 20 The Visceral Motor System 469 Overview 469 Chapter 17 Modulation of Movement by Early Studies of the Visceral Motor System 469 the Basal Ganglia 417 Distinctive Features of the Visceral Motor System 470 Overview 417 The Sympathetic Division of the Visceral Motor Projections to the Basal Ganglia 417 System 471 Projections from the Basal Ganglia to Other Brain The Parasympathetic Division of the Visceral Motor Regions 422 System 476 Evidence from Studies of Eye Movements 423 The Enteric Nervous System 479 ents of the visceral Motor System 480
xii Contents The Influence of Sensory Activity on Motor Behavior 381 Other Sensory Feedback That Affects Motor Performance 382 BOX A Locomotion in the Leech and the Lamprey 384 Flexion Reflex Pathways 387 Spinal Cord Circuitry and Locomotion 387 BOX B The Autonomy of Central Pattern Generators: Evidence from the Lobster Stomatogastric Ganglion 388 The Lower Motor Neuron Syndrome 389 BOX C Amyotrophic Lateral Sclerosis 391 Summary 391 Chapter 16 Upper Motor Neuron Control of the Brainstem and Spinal Cord 393 Overview 393 Descending Control of Spinal Cord Circuitry: General Information 393 Motor Control Centers in the Brainstem: Upper Motor Neurons That Maintain Balance and Posture 397 BOX A The Reticular Formation 398 The Corticospinal and Corticobulbar Pathways: Upper Motor Neurons That Initiate Complex Voluntary Movements 402 BOX B Descending Projections to Cranial Nerve Motor Nuclei and Their Importance in Diagnosing the Cause of Motor Deficits 404 Functional Organization of the Primary Motor Cortex 405 BOX C What Do Motor Maps Represent? 408 The Premotor Cortex 411 BOX D Sensory Motor Talents and Cortical Space 410 Damage to Descending Motor Pathways: The Upper Motor Neuron Syndrome 412 BOX E Muscle Tone 414 Summary 415 Chapter 17 Modulation of Movement by the Basal Ganglia 417 Overview 417 Projections to the Basal Ganglia 417 Projections from the Basal Ganglia to Other Brain Regions 422 Evidence from Studies of Eye Movements 423 Circuits within the Basal Ganglia System 424 BOX A Huntington’s Disease 426 BOX B Parkinson’s Disease: An Opportunity for Novel Therapeutic Approaches 429 BOX C Basal Ganglia Loops and Non-Motor Brain Functions 432 Summary 433 Chapter 18 Modulation of Movement by the Cerebellum 435 Overview 435 Organization of the Cerebellum 435 Projections to the Cerebellum 438 Projections from the Cerebellum 440 Circuits within the Cerebellum 441 BOX A Prion Diseases 444 Cerebellar Circuitry and the Coordination of Ongoing Movement 445 Futher Consequences of Cerebellar Lesions 448 Summary 449 BOX B Genetic Analysis of Cerebellar Function 450 Chapter 19 Eye Movements and Sensory Motor Integration 453 Overview 453 What Eye Movements Accomplish 453 The Actions and Innervation of Extraocular Muscles 454 BOX A The Perception of Stabilized Retinal Images 456 Types of Eye Movements and Their Functions 457 Neural Control of Saccadic Eye Movements 458 BOX B Sensory Motor Integration in the Superior Colliculus 462 Neural Control of Smooth Pursuit Movements 466 Neural Control of Vergence Movements 466 Summary 467 Chapter 20 The Visceral Motor System 469 Overview 469 Early Studies of the Visceral Motor System 469 Distinctive Features of the Visceral Motor System 470 The Sympathetic Division of the Visceral Motor System 471 The Parasympathetic Division of the Visceral Motor System 476 The Enteric Nervous System 479 Sensory Components of the Visceral Motor System 480 Purves3/eFM 5/13/04 12:59 PM Page xii
Contents xiii Central Control of Visceral Motor Functions 483 Visceral motor reflex Functions 491 Box A The Hypothalamus 484 Autonomic Regulation of Cardiovascular Function 491 Neurotransmission in the Visceral Motor System 487 Autonomic Regulation of the Bladder 493 Box B Horners Syndrome 488 Autonomic Regulation of Sexual Function 496 Box c obesity and the Brain 490 Summary 498 Unit/V THE CHANGING BRAIN Chapter 21 Early Brain Development 501 Box B Molecular Signals That Promote Synapse Overview 501 Formation 542 The Initial Formation of the Nervous System Trophic Interactions and the Ultimate Size of Neuronal Gastrulation and Neurulation 501 Populations 543 The Molecular Basis of Neural Induction 503 Further Competitive Interactions in the Formation of BOx A Stem Cells: Promise and Perils Neuronal Connections 545 504 BoX B Retinoic Acid: Teratogen and Inductive Molecular Basis of Trophic Interactions 547 Box C Why Do Neurons Have Dendrites?548 Formation of the major Brain Subdivisions 510 Box D The Discovery of BDNF and the Box C Homeotic Genes and Human Brain Neurotrophin Family 552 evelopment 513 neurotrophin Signaling 553 Box D Rhombomeres 514 Summary 554 Genetic Abnormalities and Altered Human brain Development 515 Chapter 23 Modification of Brain Circuits The Initial Differentiation of Neurons and Glia 516 as a Result of Experience 557 Box E Neurogenesis and Neuronal Birthdating Overview 557 517 Critical Periods 557 The Generation of Neuronal Diversity 518 Box A Built-In Behaviors 558 Neuronal Migration 520 The Development of Language Box F Mixing It Up: Long-Distance Neuronal Example of a Human Critical Period 559 Migration 524 Box B Birdsong 560 Summary 525 Critical Periods in Visual System Development 562 Effects of Visual Deprivation on Ocular Dominance 563 Chapter 22 Construction of Neural Box C Transneuronal Labeling with Radioactive Circuits 527 Amino Acids 564 Overview 527 isual Deprivation and Amblyopia in Humans 568 The Axonal Growth Cone 527 Mechanisms by which Neuronal Activity Affects the Non-Diffusible Signals for Axon Guidance 52 Development of Neural Circuits 569 Box A Choosing Sides: Axon Guidance at the Cellular and Molecular Correlates of Activity Optic Chiasm 530 Dependent Plasticity during Critical Periods 572 Chemoattraction and Repulsion ce Diffusible Signals for Axon Guidar Evidence for Critical Periods in Other Sensor 534 The Formation of Topographic Maps 537 Summary 573 Selective Synapse Formation 539
Chapter 21 Early Brain Development 501 Overview 501 The Initial Formation of the Nervous System: Gastrulation and Neurulation 501 The Molecular Basis of Neural Induction 503 BOX A Stem Cells: Promise and Perils 504 BOX B Retinoic Acid: Teratogen and Inductive Signal 506 Formation of the Major Brain Subdivisions 510 BOX C Homeotic Genes and Human Brain Development 513 BOX D Rhombomeres 514 Genetic Abnormalities and Altered Human Brain Development 515 The Initial Differentiation of Neurons and Glia 516 BOX E Neurogenesis and Neuronal Birthdating 517 The Generation of Neuronal Diversity 518 Neuronal Migration 520 BOX F Mixing It Up: Long-Distance Neuronal Migration 524 Summary 525 Chapter 22 Construction of Neural Circuits 527 Overview 527 The Axonal Growth Cone 527 Non-Diffusible Signals for Axon Guidance 528 BOX A Choosing Sides: Axon Guidance at the Optic Chiasm 530 Diffusible Signals for Axon Guidance: Chemoattraction and Repulsion 534 The Formation of Topographic Maps 537 Selective Synapse Formation 539 BOX B Molecular Signals That Promote Synapse Formation 542 Trophic Interactions and the Ultimate Size of Neuronal Populations 543 Further Competitive Interactions in the Formation of Neuronal Connections 545 Molecular Basis of Trophic Interactions 547 BOX C Why Do Neurons Have Dendrites? 548 BOX D The Discovery of BDNF and the Neurotrophin Family 552 Neurotrophin Signaling 553 Summary 554 Chapter 23 Modification of Brain Circuits as a Result of Experience 557 Overview 557 Critical Periods 557 BOX A Built-In Behaviors 558 The Development of Language: Example of a Human Critical Period 559 BOX B Birdsong 560 Critical Periods in Visual System Development 562 Effects of Visual Deprivation on Ocular Dominance 563 BOX C Transneuronal Labeling with Radioactive Amino Acids 564 Visual Deprivation and Amblyopia in Humans 568 Mechanisms by which Neuronal Activity Affects the Development of Neural Circuits 569 Cellular and Molecular Correlates of ActivityDependent Plasticity during Critical Periods 572 Evidence for Critical Periods in Other Sensory Systems 572 Summary 573 Contents xiii Unit IV THE CHANGING BRAIN Central Control of Visceral Motor Functions 483 BOX A The Hypothalamus 484 Neurotransmission in the Visceral Motor System 487 BOX B Horner’s Syndrome 488 BOX C Obesity and the Brain 490 Visceral Motor Reflex Functions 491 Autonomic Regulation of Cardiovascular Function 491 Autonomic Regulation of the Bladder 493 Autonomic Regulation of Sexual Function 496 Summary 498 Purves3/eFM 5/13/04 12:59 PM Page xiii
