Development of the Nervous System (eBook)

Cover 1
Contents 8
Preface to the First Edition 12
Preface to the Second Edition 14
Chapter 1: Neural Induction 16
Development and Evolution of Neurons 16
Early Embryology of Metazoans 16
Derivation of Neural Tissue 18
Interactions with Neighboring Tissues in Making Neural Tissue 24
The Molecular Nature of the Neural Inducer 28
Conservation of Neural Induction 31
Interactions Among the Ectodermal Cells in Controlling Neuroblast Segregation 35
Notch, Delta, and Achaete Scute Genes in Vertebrates 40
Linking Induction to Proneural Activity 42
Summary 43
Chapter 2: Polarity and Segmentation 44
Regional Identity of the Nervous System 44
The Anterior-Posterior Axis and HOX Genes 45
HOX Gene Function in the Nervous System 48
Signaling Molecules that Pattern the Anterior-Posterior Axis in Vertebrates: Heads or Tails 51
Organizing Centers in the Developing Brain 54
Forebrain Development, Prosomeres, and PAX Genes 57
Dorsal-Ventral Polarity in the Neural Tube 61
Dorsal Neural Tube and Neural Crest 65
Patterning the Cerebral Cortex 67
Summary 70
Chapter 3: Genesis and Migration 72
Cell-Cycle Genes Control the Number of Neurons Generated during Development 77
Cell Interactions Control the Number of Cells Made by Progenitors 78
The Generation of Neurons and GLIA 84
Cerebral Cortex Histogenesis 86
The Subventricular Zone: A Secondary Zone of Neurogenesis 90
Cerebellar Cortex Histogenesis 91
Molecular Mechanisms of Neuronal Migration 93
Postembryonic and Adult Neurogenesis 97
Summary 100
Chapter 4: Determination and Differentiation 102
Transcriptional Hierarchies in Invariant Lineages 103
Spatial and Temporal Coordinates of Determination 106
Asymmetric Cell Divisions and Asymmetric Fate 108
Generating Complexity through Cellular Interactions 109
Specification and Differentiation through Cellular Interactions and Interactions with the Local Environment 112
Competence and Histogenesis 115
The Interplay of Intrinsic and Extrinsic Influences in Histogenesis 117
Interpreting Gradients and the Spatial Organization of Cell Types 121
Summary 124
Chapter 5: Axon Growth and Guidance 126
The Growth Cone 129
The Dynamic Cytoskeleton 131
What Do Growth Cones Grow On? 136
What Provides Directional Information to Growth Cones? 138
Cell Adhesion and Labeled Pathways 139
Repulsive Guidance 142
Chemotaxis, Gradients, and Local Information 145
The Optic Pathway 148
The Midline 149
Attraction and Repulsion: Desensitization and Adaptation 149
Signal Transduction 152
Summary 153
Chapter 6: Target Selection 160
Defasiculation 160
Target Recognition and Entry 162
Slowing Down and Branching 163
Border Patrol and Prevention of Inappropriate Targeting 164
Topographic Mapping 167
Chemospecificity and Ephrins 168
Shifting and Fine Tuning of Connections 173
The Third Dimension, Lamina-Specific Termination 177
Cellular and Synaptic Targeting 179
Sniffing Out Targets 181
Summary 185
Chapter 7: Naturally Occurring Neuron Death 188
What does Neuron Death Look Like? 188
Early Elimination of Progenitor Cells 189
How Many Differentiated Neurons Die? 189
Survival Depends on the Synaptic Target 191
NGF: A Target-Derived Survival Factor 195
The Neurotrophin Family 197
The TRK Family of Neurotrophin Receptors 199
How does the Neurotrophin Signal Reach the Soma? 201
The P75 Neurotrophin Receptor 201
The Expanding World of Survival Factors 203
Endocrine Control of Cell Survival 205
Cell Death Requires Protein Synthesis 207
Intracellular Signaling 208
Caspases: Agents of Death 211
BCL-2 Proteins: Regulators of Apoptosis 215
Synaptic Transmission at the Target 216
Afferent Regulation of Cell Survival 217
Summary 221
Chapter 8: Synapse Formation and Function 222
What Do Newly Formed Synapses Look Like? 226
The First Signs of Synapse Function 230
The Decision to Form a Synapse 233
The Sticky Synapse 235
Converting Growth Cones to Presynaptic Terminals 236
Receptor Clustering Signifies Postsynaptic Differentiation at NMJ 237
Presynaptic Terminals Induce Receptor Aggregation 239
Agrin, a Transynaptic Clustering Signal 241
Postsynaptic Response to Agrin 242
Receptor Clustering Signals in the CNS 244
Internal Membrane Proteins and Receptor Aggregation in the CNS 245
The Expression and Insertion of New Receptors 248
Neuronal Activity Regulates Receptor Expression 250
Neuregulin, a Regulator of Postsynaptic Transcription 251
Maturation of Transmission and Receptor Isoform Transitions 253
Maturation of Transmitter Reuptake 256
Short-Term Plasticity 257
Appearance of Synaptic Inhibition 258
Is Inhibition Really Inhibitory during Development? 258
Summary 259
Chapter 9: Refinement of Synaptic Connections 262
The Early Pattern of Connections 262
Functional Synapses are Eliminated 264
Axonal Arbors are Refined or Eliminated 265
Some Terminals Expand or Remain Stable 270
Neural Activity Regulates Synaptic Connections 270
Sensory Coding Properties Reflect Synapse Rearrangement 277
Activity Contributes to the Alignment of Sensory Maps 280
Spontaneous Activity and Afferent Segregation 282
Many Forms of Plasticity have a Time Limit 286
Synapses Interact Over a Short Distance 286
Heterosynaptic Depression 287
Postsynaptic Receptors are Eliminated 289
Involvement of Intracellular Calcium 291
NMDA Receptors and Calcium Signaling 291
The Role of Second Messenger Systems 293
Metabotropic Receptors 294
Gain Control 295
Silent Synapses 297
Homeostasis: The More Things Change, the More They Stay the Same 298
Plasticity of Inhibitory Connections 299
Synaptic Influence on Neuron Morphology 300
Summary 302
Chapter 10: Behavioral Development 304
Behavioral Ontogeny 304
Genetic and Environmental Mechanisms 305
Environmental Determinants of Behavioral Development 306
The First Movements 306
The Mechanism of Spontaneous Movements 308
Embryonic Movements: Uncoordinated or Integrated? 309
The Role of Activity in the Emergence of Coordinated Behavior 311
Stage-Specific Behaviors 312
Beginning to Make Sense of the World 314
Asking Babies Questions 315
Sharp Eyesight 316
Acute Hearing 317
Sex-Specific Behavior 320
Genetic Sex 321
Hormonal Signals 321
Hormonal Control of Brain Gender 322
Genetic Control of Brain Gender 323
Singing in the Brain 324
From Gonads to Brain? 325
Learning to Remember 326
Where’s Mamma? 327
Fear and Loathing 329
Getting Information from One Brain to Another 332
Language 334
Summary 336
References 338
Index 376