1 Effects of Drugs on Energy Metabolism of the Brain and on Cerebral Transport.- 1. Introduction.- 2. Drugs and Brain Cell Energetics.- 3. Neurotropic Drugs Affecting Electron and Energy Transfer.- 4. Drugs and Brain Cell Permeabilities.- 5. Drugs Affecting Cerebral Biogenic Amine Levels.- 6. Ethanol.- 7. References.- 2 Role of Cyclic Nucleotides in the Nervous System.- 1. Introduction.- 2. Enzymatic Formation, Degradation, and Action of Cyclic Nucleotides.- 3. Accumulation of Cyclic Nucleotides.- 4. Functional Roles of Cyclic Nucleotides.- 5. Conclusion.- 6. References.- 3 Purinergic Transmission.- 1. Introduction.- 2. Distribution of Purinergic Nerves.- 3. Fine Structure and Histochemistry of Purinergic Nerves.- 4. Electrophysiology of Purinergic Transmission.- 5. Physiological Roles of Purinergic Nerves.- 6. Evidence that ATP is the Purinergic Nerve Transmitter.- 7. Pharmacology of Adenyl Compounds and Purinergic Transmission.- 8. Speculations on the Evolution and Development of Purinergic Nerves.- 9. Summary.- 10. References.- 4 Hypothalamic Hypophysiotropic Hormones.- 1. Introduction.- 2. Hypophysiotropic Hormone Action.- 3. Thyrotropin Releasing Factor (TRF).- 4. Luteinizing Hormone Releasing Factor (LRF).- 5. Corticotropin Releasing Factor (CRF).- 6. Prolactin Release Inhibiting Factor (PIF).- 7. Growth Hormone Releasing Factor (GRF).- 8. Somatostatin-Somatotropin Release Inhibiting Factor (SRIF).- 9. References.- 5 Binding, Metabolism, and Action of Steroid Hormones in the Central Nervous System.- 1. Introduction.- 2. Estrogens.- 3. Androgens.- 4. Glucocorticoids.- 5. Progestins.- 6. Conclusion.- 7. References.- 6 Opiate Receptor Mechanisms.- 1. Introduction.- 2. Biochemical Identification of Opiate-Receptor Binding.- 3. Localization of the Opiate Receptor to Synaptic Membranes.- 4. Regional Distribution of Opiate-Receptor Binding.- 5. Effect of Destruction of Norepinephrine, Serotonin, Acetylcholine, and Dopamine Tracts on Opiate-Receptor Binding.- 6. Phylogenetic Distribution of the Opiate Receptor.- 7. Effect of Sodium on Opiate-Receptor Binding.- 8. Toward a Theory of Addiction.- 9. References.- Addendum to Chapter 2.