Main description:

The previous volumes in this series have dealt with the mature cerebral cortex. In those volumes many of the structurally and physiologically distinct areas of the cerebral cortex, their connections, the various types of neurons and neuroglial cells they contain, and the functions of those cells have been considered. In the present volume the contributions focus on the development of the neocortex and hippocampus. Chapters in this volume describe how the neurons migrate in the cortex to attain their ultimate positions, and emphasize the role played by the preexisting pallium or primordial plexiform layer of the cerebral vesicle in the development of the cerebral cortex. The primordial plexiform layer becomes split by the invasion of neurons that will form the cortical plate, and mutants in which the neuronal migration is abnormal provide valuable information about the role of the radial glial cells in this migration. It is also made clear that although the mechanics of development in the hippocampus are similar to those in the neocortex, the development of the hippocampus involves some unique features. For example, neuronal proliferation in the dentate gyrus continues well into postnatal life.

Contents:

1 Early Ontogenesis of the Human Cerebral Cortex.- 1. Introduction.- 2. Historical Perspectives.- 3. Origin and Early Ontogenesis of the Human Cerebral Cortex.- 3.1. Human Embryonic Stage 15 (ca. 33 Days; ca. 7-9 mm).- 3.2. Human Embryonic Stage 17 (ca. 41 Days; ca. 11-14 mm).- 3.3. Human Embryonic Stage 18 (ca. 44 Days; ca. 13-17 mm).- 3.4. Human Embryonic Stage 20 (ca. 51 Days; ca. 18-22 mm).- 3.5. Human Embryonic Stage 22 (ca. 54 Days; ca. 23-28 mm).- 4. Differentiation and Maturation of the Mammalian Cortical Plate.- 5. Conclusions.- 6. References.- 2 The Role of the Subplate in the Development of the Mammalian Telencephalon.- 1. Introduction.- 2. Development of Geniculocortical Connections.- 3. Neurogenesis of Cortical Layer 4.- 4. Cellular Organization of the White Matter during Development.- 5. The Subplate Is a Transient Synaptic Neuropil.- 6. The Subplate and Marginal Zones Contain a Transient Class of Peptide-Immunoreactive Neuron.- 7. The Role of Subplate Neurons in Cortical Development.- 8. References.- 3 The Reeler Malformation: Implications for Neocortical Histogenesis.- 1. Introduction.- 1.1. The Reeler Phenotype.- 1.2. Genetics and Comparative Teratology.- 2. Neuronal Migration.- 2.1. Patterns of Neurogenesis and Migration.- 2.2. Cellular Interactions Critical to Neuronal Migration.- 3. Neuron Position and Secondary Events of Neocortical Histogenesis.- 3.1. Axonal and Dendritic Growth in Normal Development.- 3.2. Axonal and Dendritic Growth in the Reeler Mutant.- 4. Recapitulation and Implications.- 5. References.- 4 The Development of the Hippocampal Region.- 1. Introduction.- 2. The Hippocampal Region in the Adult Brain.- 2.1. The Entorhinal Cortex.- 2.2. The Subicular Complex.- 2.3. Ammon's Horn or the Hippocampus Proper.- 2.4. The Dentate Gyrus.- 3. The Generation of Neurons in the Hippocampal Region.- 3.1. The Generation of Neurons in the Hippocampus and in the Retrohippocampal Region.- 3.2. The Generation of Neurons in the Dentate Gyrus.- 4. The Migration of the Neurons in the Hippocampal Region.- 4.1. The Migration of Neurons in Ammon's Horn and in the Retrohippocampal Region.- 4.2. The Migration of Neurons in the Dentate Gyrus.- 5. The Development of Neuronal Form in the Hippocampal Region.- 6. The Development of the Afferents to the Hippocampal Region.- 7. The Development of Efferents from the Hippocampal Region.- 8. Other Aspects of the Development of the Hippocampal Region.- 9. References.- 5 Development of Projection and Local Circuit Neurons in Neocortex.- 1. Introduction.- 2. Projection Neurons.- 2.1. Proliferation.- 2.2. Migration.- 2.3. Morphological Differentiation.- 2.4. Neurochemical Differentiation.- 3. Local Circuit Neurons.- 3.1. Proliferation.- 3.2. Migration.- 3.3. Morphological Differentiation.- 3.4. Neurochemical Differentiation.- 4. Summary and Conclusions.- 5. References.- 6 Changes in Neurotransmitters during Development.- 1. Introduction.- 2. Excitatory Amino Acids.- 3. Acetylcholine.- 4. GABA.- 5. Neuropeptides.- 5.1. Somatostatin.- 5.2. Neuropeptide Y.- 5.3. Vasoactive Intestinal Polypeptide.- 5.4. Cholecystokinin.- 6. Monoamines.- 6.1. Noradrenaline.- 6.2. 5-Hydroxytryptamine (Serotonin).- 6.3. Dopamine.- 7. References.- 7 Biochemistry of Neurotransmitters in Cortical Development.- 1. Introduction.- 2. Afferent Pathways to Cortex.- 2.1. Noradrenergic Cortical Projections.- 2.2. Dopamine Projections.- 2.3. Serotonin Innervation.- 2.4. Cholinergic Innervation.- 3. Intrinsic Cortical Neurons.- 3.1. GABA-Containing Neurons.- 3.2. Vasoactive Intestinal Peptide-Containing Neurons.- 3.3. Somatostatin Neurons.- 3.4. Cholecystokinin Neurons.- 3.5. Other Peptidergic Cortical Neurons.- 4. Glutamate Pathways.- 4.1. Excitatory Amino Acid Receptors.- 4.2. Glutamate-Stimulated PI Turnover.- 5. Conclusion.- 6. References.- 8 The Physiology of Developing Cortical Neurons.- 1. Introduction.- 2. Spontaneous Unitary Activity.- 3. Evoked Potentials in Immature Neocortex.- 3.1. Bias in Activity Revealed by Evoked Potentials.- 3.2. Laminar Development of Synaptic Activity.- 4. Postsynaptic Potentials in Immature Cortical Cells.- 4.1. Morphological and Neurochemical Substrates for EPSP and IPSP Generation.- 4.2. Postsynaptic Potentials and Field Potentials.- 5. Latencies of Evoked Neuronal Activity.- 6. Nature of Unit Responses in Immature SmI Cortex.- 6.1. Genesis of Unit Responses.- 6.2. Following Frequency.- 6.3. Response Pattern and Inhibition.- 7. Receptive Field Organization in Immature SmI Cortex.- 7.1. Kitten SmI Cortex.- 7.2. Neonatal Rat SmI Cortex.- 8. Cortical Morphology and Functional Development.- 9. Laminar Development of Visual Cortex.- 10. Receptive Field Organization in Immature Visual Cortex.- 10.1. Receptive Field Size.- 10.2. Receptive Field Structure.- 10.3. Orientation Selectivity.- 10.4. Ocular Dominance.- 11. Conclusions.- 12. References.- 9 Changes in Cytoskeletal Elements during Postnatal Development of Cerebral Cortex.- 1. Introduction.- 2. Composition of Neuronal Cytoskeleton.- 2.1. Microfilaments.- 2.2. Microtubules.- 2.3. Intermediate Filaments.- 3. Heterogeneity.- 3.1. Actin Heterogeneity.- 3.2. Tubulin Heterogeneity.- 3.3. Neurofilament Heterogeneity.- 4. Distribution.- 4.1. Distribution of Microtubules and Neurofilaments in Nervous Tissue.- 4.2. Distribution of Actin and Actin Filaments.- 5. Potential Functions of Cytoskeletal Elements in Nerve Cells.- 5.1. Role of Microtubules and Neurofilaments.- 5.2. Role of Actin.- 5.3. Role of Brain Spectrin.- 6. Cytoskeletal Changes during Postnatal Brain Development.- 6.1. Developmental Changes in Tubulin and Microtubules.- 6.2. Developmental Changes in Actin and Microfilaments.- 6.3. Developmental Changes in Neurofilament Components.- 6.4. Developmental Changes in Glial Fibrillary Acidic Protein.- 7. The Cytoskeleton and Functionally Driven Plasticity.- 7.1. The Influence of Electrical Activation on Neuronal Connectivity.- 7.2. Critical Period Plasticity.- 8. References.- 10 Development of Visual and Auditory Cortical Connections in the Cat.- 1. Introduction.- 2. Development of Cerebral Hemispheres and Commissures.- 2.1. Development of Gross Structures.- 2.2. Development of Microscopic Structures.- 3. General Considerations of Pathway Tracing Techniques in Immature Animals.- 4. Organization of Corticosubcortical Projections during Development.- 4.1. Overview.- 4.2. Development of Projections.- 5. Organization of Corticocortical Projections during Development.- 5.1. Interhemispheric Projections.- 5.2. Ipsilateral Transcortical Projections.- 5.3. Reorganization of Interhemispheric and Transcortical Projections.- 6. Synapse Formation and Receptor Appearance.- 7. Development of Functional Connections.- 7.1. Visual Cortex.- 7.2. Auditory Cortex.- 8. Experientially Induced Reorganization of Cortical Connections.- 8.1. Visual Cortex.- 8.2. Auditory Cortex.- 9. Cortical Ablation Studies.- 9.1. Anatomical Studies.- 9.2. Physiological Studies.- 9.3. Behavioral Studies.- 10. Conclusions and Speculations.- 11. References.- 11 Plasticity of Synapse Structure and Pattern in the Cerebral Cortex.- 1. Introduction.- 2. Evidence for Changes in Preexisting Synapses.- 2.1. Experience Effects on the Size of Synapses.- 2.2. Number, Density, and Location of Vesicles.- 2.3. Conformation of the Contact or Apposition Zone.- 2.4. Spine Shape Modulation.- 2.5. Subsynaptic Plate Perforations.- 3. Synaptic Number and Pattern Changes.- 3.1. Mechanisms of Experiential Modulation of Synaptogenesis in Early Development.- 3.2. Dentritic Pattern Generated by Selective Preservation and Selective Growth.- 3.3. Capacity for Synaptogenesis Continues beyond Early Development.- 3.4. Functional Roles of Changes in Synaptic Connection Patterns.- 3.5. Tests of Other Possible Causes of Synaptic Number Changes.- 3.6. Persistence of Experience-Related Synaptic Number Changes.- 4. How Do Synapse Number Changes Arise? Developmental and Mature Forms of Synaptogenesis.- 5. Other Features of Developmental Plasticity of Cerebral Cortex.- 5.1. Developmental Plasticity of Associated Tissue Elements.- 5.2. Neuromodulation of Developmental Plasticity: A Case Study.- 5.3. Multivariate Statistical Approaches to Relations among Diverse Morphological Measures.- 6. Concluding Comments.- 7. References.- 12 Effects of Nutrition on Cortical Development.- 1. Introduction.- 2. Historical Perspectives.- 3. Animal Models.- 3.1. Malnutrition or Undernutrition?.- 3.2. Timing, Duration, and Severity.- 3.3. Methodology.- 4. General Morphological Effects of Experimentally Induced Undernutrition.- 4.1. Somatic Effects.- 4.2. Brain Weights.- 5. Histological Studies on the Brains of Undernourished Animals.- 5.1. Methodological Considerations.- 5.2. Effects of Undernutrition on Cortical Structure.- 6. Undernutrition and Environment.- 6.1. Brain Weights and Cortical Thickness.- 6.2. Neuronal and Glial Cell Measurements.- 6.3. Synaptic Measurements.- 7. Concluding Remarks.- 8. References.- 13 Embryonic Vascularization of the Mammalian Cerebral Cortex.- 1. Introduction.- 2. Materials and Methods.- 3. The Endothelial Cell of CNS Growing Capillaries.- 4. CNS Capillary Angiogenesis, Anastomosis, and Lumen Formation.- 5. Embryonic Vascularization of Cerebral Cortex.- 5.1. Perineural Vascular Territory and Meningeal Compartment.- 5.2. Interneural Vascular Territory and Virchow-Robin Compartment.- 5.3. Intraneural Vascular Territory and Perivascular Glial Compartment.- 6. Conclusions.- 7. References.