I. Organization.- 1. Fiber architecture of the Hippocampal Formation: Anatomy, Projections, and Structural Significance.- 1. Introduction.- 2. Limbic Lobe.- 3. Anatomy of the Hippocampal Formation.- 4. Hippocampal Formation: External Afferent Supply.- 4.1. Lateral Input System (Through Entorhinal Area).- 4.2. Supracallosal Input.- 4.3. Fornix-Fimbrial Fibers.- 5. Hippocampal Formation: Commissural Connections.- 6. Hippocampal Formation: Internal Afferents.- 7. Hippocampal Efferents.- 8. Conclusion.- 9. Addendum.- 10. References.- 2. Septohippocampal Interface.- 1. Introduction.- 2. Connections Between the Septum and the Hippocampus.- 2.1. Hippocamposeptal.- 2.2. Septohippocampal.- 2.3. Indirect Connections.- 3. Major Outputs of the Septum and the Hippocampus.- 3.1. Mammillary Projections.- 3.2. Thalamic Projections.- 4. Summary and Conclusions.- 5. Appendix: Comments on Stains.- 5.1. Cell Stains.- 5.2. Fiber Stains.- 5.3. Autoradiography.- 5.4. Histochemical Neuroanatomy.- 6. References.- 3. Development of the Hippocampal Region.- 1. Introduction.- 2. Terminology and Orientation.- 3. Definition of Areas.- 4. Comparative Neuroanatomical Aspects—Evolution of the Region.- 4.1. Cyclostomes.- 4.2. Cartilaginous Fishes.- 4.3. Bony Fishes.- 4.4. Amphibians.- 4.5. Reptiles.- 4.6. Birds.- 4.7. Mammals.- 5. Morphogenetic Aspects—Shaping of the Region.- 5.1. Classical Studies.- 5.2. Autoradiographic Studies.- 5.3. Other Studies and Approaches for the Future.- 6. References.- 4. Postnatal Development of the Hippocampal Dentate Gyrus Under Normal and Experimental Conditions.- 1. Introduction.- 2. Normal Development of the Dentate Gyrus.- 2.1. Cytogenesis.- 2.2. Morphogenesis.- 2.3. Synaptogenesis.- 2.4. Gliogenesis and Myelogenesis.- 3. Development of the Dentate Gyrus Under Experimental Conditions.- 3.1. Effects of Interference with Cytogenesis.- 3.2. Effects of Interference with Morphogenesis.- 4. References.- 5. The Hippocampus as a Model for Studying Anatomical Plasticity in the Adult Brain.- 1. Introduction.- 2. Studies on Sprouting Outside the Hippocampus.- 2.1. Light Microscopic Studies.- 2.2. Electron Microscopic Studies.- 2.3. Negative Results.- 3. Studies on Sprouting in the Hippocampus.- 3.1. Studies with Adult Rats.- 3.2. Studies with Immature Rats.- 3.3. Negative Results.- 4. Status of Sprouting in the Brain.- 5. Hypotheses Regarding Mechanisms Controlling Sprouting in the Hippocampus.- 5.1. Initiation.- 5.2. Principles for the Reorganization of Terminal Fields.- 6. Conclusion and Summary.- 7. References.- 6. Organization of Hippocampal Neurons and Their Interconnections.- 1. Extrinsic Connections of the Hippocampus.- 1.1. The Perforant Path.- 1.2. Other Afferents to the Dentate Area.- 1.3. Afferents to the CA3 Region.- 1.4. Afferents to the CA1 Region.- 1.5. Afferents to the Subiculum.- 2. Intrinsic Connections: Basket Cell Inhibition.- 3. Output from the Hippocampal Formation.- 4. Lamellar Organization of the Hippocampal Formation.- 5. Frequency Characteristics of Hippocampal and Dentate Synapses.- 6. Localization of Synapses on Hippocampal Neurons and Axons.- 7. Localization of Putative Transmitters in the Hippocampal Formation.- 8. References.- 7. An Ongoing Analysis of Hippocampal Inputs and Outputs: Microelectrode and Neuroanatomical Findings in Squirrel Monkeys.- 1. Introduction.- 1.1. Evolutionary Considerations.- 1.2. The Problem of “Sensory” Inputs.- 1.3. Antecedent Findings.- 2. Microelectrode and Anatomical Findings on Limbic Inputs.- 2.1. Methods.- 2.2. Visual Input.- 2.3. Comment.- 2.4. “Approach-Type” Units.- 2.5. Auditory Input.- 2.6. Somatic Input.- 2.7. Gustatory Stimulation.- 2.8. Comment.- 2.9. Stimulation of Olfactory Bulb.- 2.10. Vagal Input.- 2.11. The Question of Limbic Sensory Integration.- 2.12. Inputs to Hypothalamus.- 3. Hippocampal Influence on the Brain Stem.- 3.1. Neuroanatomical Correlations.- 3.2. Dorsal Thalamus.- 3.3. Comment.- 4. Conclusion and Summary.- 5. References.- II. Neurochemistry and Endocrinology.- 8. Monoamine Neurons Innervating the Hippocampal Formation and Septum: Organization and Response to Injury.- 1. Introduction.- 2. Organization of Hippocampal and Septal Monoamine Innervation.- 2.1. Hippocampal Formation.- 2.2. Septum.- 3. Response to Injury of Hippocampal and Septal Monoamine Innervation.- 3.1. Regeneration of the Transected Axon.- 3.2. Collateral Reinnervation.- 4. Conclusions.- 5. References.- 9. Neurotransmitters and the Hippocampus.- 1. Introduction.- 2. Techniques.- 2.1. Release Studies.- 2.2. Identity of Action.- 3. Transmitter Substances.- 3.1. Acetylcholine.- 3.2. Inhibitory Amino Acids.- 3.3. Other Putative Transmitters.- 4. Conclusions.- 5. References.- 10. Cholinergic Neurons: Septal-Hippocampal Relationships.- 1. Introduction.- 2. Localization of Cholinergic Neurons in Mammalian Central Nervous System.- 2.1. The Histochemical Method for Acetylcholinesterase.- 2.2. The Histochemical Method for Choline Acetyl transferase.- 3. Evidence for a Septal-Hippocampal Pathway.- 3.1. Anatomy of the Hippocampus.- 3.2. Histochemical and Biochemical Studies.- 4. Electrophysiological Studies.- 5. Sprouting of Cholinergic Neurons After Cortical Injury.- 6. Biochemical Experiments.- 7. References.- 11. Putative Glucocorticoid Receptors in Hippocampus and Other Regions of the Rat Brain.- 1. Introduction.- 2. Cellular Mechanisms of Hormone Action.- 3. Studies of Putative Estrogen Receptors in Brain.- 4. Glucocorticoid Interaction with Rat Brain: Preferential Uptake by Hippocampus.- 5. Subcellular Localization of [3H] Corticosterone Binding Sites in Hippocampus.- 6. Soluble Glucocorticoid Binding Proteins in Brain and Other Target Tissues.- 7. Study of Cellular Mechanism of [3H] Corticosterone Entry into Hippocampal Cell Nuclei.- 8. Factors Affecting Amount of Glucocorticoid Binding Protein in Hippocampus.- 9. Adrenal Steroid and Brain Chemistry.- 10. Neurochemistry of the Hippocampus.- 11. Adrenal Glucocorticoids and Limbic Control of Pituitary Function.- 12. Adrenal Steroid Effects on Detection and Recognition of Sensory Stimuli.- 13. Pituitary-Adrenal System and Stress-Related Behavior.- 14. Pituitary-Adrenal Axis, Hippocampus, and Behavior.- 15. References.- 12. The Hippocampus and the Pituitary-Adrenal System Hormones.- 1. Introduction.- 2. Septal-Hippocampal Function and Release of Pituitary-Adrenal System Hormones.- 3. Pituitary-Adrenal System Hormones and Functional Activity of the Septal-Hippocampal Complex: Endocrine Aspects.- 4. Pituitary-Adrenal System Hormones and Functional Activity of the Septal-Hippocampal Complex: Behavioral Aspects.- 5. The Septal-Hippocampal System: Is It the Substrate of the Behavioral Effect ofACTH and Related Peptides?.- 6. General Discussion and Conclusions.- 7. References.- 13. The Hippocampus and Hormonal Cyclicity.- 1. Introduction.- 2. Gonadal Hormones and Cyclicity.- 2.1. Electrical Activity: Spontaneous, Evoked, and Multiple Unit.- 2.2. Effects of Lesion and Stimulation.- 3. Adrenocortical Hormones and Sensory Information Processing.- 4. Adrenocortical Hormones and Cyclicity.- 5. New Horizons.- 6. References.- 14. The Hippocampus and Regulation of the Hypothalamic- Hypophyseal-Adrenal Cortical Axis.- 1. Introduction.- 2. Diurnal Rhythms and Responses to Stress: Different Functional Systems.- 3. The Hippocampus and Regulation of Circadian Rhythm of Corticosteroid Hormone.- 3.1. Fornix Section.- 3.2. Hippocampal Steroid Implants.- 3.3. Summary.- 4. The Hippocampus and Regulation of Corticosteroid Responses to Stress.- 4.1. Electrical Stimulation of Hippocampus.- 4.2. Ablation of Hippocampus.- 4.3. Hippocampus and Adrenocortical Feedback Mechanisms.- 4.4. Hippocampal Steroid Implants.- 4.5. Summary.- 5. References.- 15. Hippocampal Protein Synthesis and Spike Discharges in Relation to Memory.- 1. Introduction.- 2. Macro molecular Synthesis in the Hippocampus.- 2.1. Macromolecular Theory of Flexner.- 2.2. Enhancement of Macromolecular Synthesis.- 3. Effects of Epileptogenic Substances.- 3.1. Actinomycin D.- 3.2. Puromycin.- 3.3. Penicillin.- 4. Disruptive Stimulation of the Hippocampus.- 4.1. Potassium Chloride.- 4.2. Acute Lesions.- 4.3. Cholinergic Stimulation.- 5. Retrograde Amnesia by Electrical Stimulation.- 5.1. Stimulation of the Hippocampus.- 5.2. Stimulation of Other Structures.- 5.3. Kindling.- 6. Mechanisms Underlying the Amnesic Effect.- 7. References.