Effects of Antidepressants on Transmembrane Signaling.- Role of G Proteins in Signal Transduction.- Effects of Chronic Administration of Antidepressants on Signal Transduction.- The Phospholipase C System in Affective Disorders.- Targets for Antidepressants.- References.- Serotonergic and Noradrenergic Neuromodulation in the Hippocampus and the Mechanism of Action of Antidepressants.- Pathophysiological Model of Affective Disorders and Monoaminergic Function.- Development of Novel Antidepressants and Their Pharmacological Profiles.- Modulation of Serotonergic Neurotransmission by SSRIs.- Convergence of Serotonergic and Noradrenergic Neurotransmission: Neurodynailiic Viewpoint.- Conclusion.- References.- Serotonin-2A Receptor Function in Affective Disorders.- Role of 5-HT2A Receptor Function in Etiology of Affective Disorders.- Postmortem Brain Studies.- Neuroendocrine Studies.- Platelet Studies.- Calcium Mobilization and Affective Diosorders.- 5-HTMnduced Calcium Response in Nonmedicated Depressed Patients.- Change in 5-HT-Induced Calcium Response During Drug Treatment.- Other Calcium Studies.- Mechanism of 5-HT2A Receptor Hyperfunction.- Conclusion.- References.- Immunological Aspects of Mood Disorders: Interaction Between Cytokines and Intracellular Calcium Signaling.- Immunological Dysfunction in Mood Disorders.- Stress and Immunological Function.- Alteration of Immune Function and Mood.- Cytokines and Nitric Oxide Pathway.- Cytokines and Calcium Function.- Conclusion.- References.- The Role of G Proteins in the Pathophysiology and Treatment of Affective Disorders.- Changes in the Biological Hypotheses for the Pathophysiology of Manic-Depressive Illness.- Antidepressants and G Proteins.- Receptors and G Proteins.- G Protein and Adenylyl Cyclase.- Direct Action on G Protein.- Receptor Reconciliation Theory of the Action of Antidepressants.- Postmortem Study in Affective Disorders.- Postnatal Developmental Changes of G Protein in Human Brains.- Imbalance Hypothesis of G-Protein Function in Affective Disorders.- Selectivity of Treatment Drugs in the Light of Signal Transduction.- Conclusion.- References.- Protein Phosphorylation System in the Mechanism of Action of Antidepressants.- Protein Phosphorylation Systems.- cAMP-Dependent Phosphorylation System.- Effect of Antidepressant Treatment on the PKA System.- Effect of Antidepressant Treatment on Phosphorylation of Substrate Proteins for PKA.- Effect of Antidepressant Treatment on Phosphorylation of MAP2.- Effect of Antidepressant Treatment on Microtubule Assembly.- Conclusion.- References.- Stress and BDNF Signal Transduction: Implications for Stress-Related Psychiatric Disorders.- Physiological Functions of BDNF.- Regulation of BDNF Expression.- BDNF Signal Transduction Cascade.- Stress-Induced Hippocampal Cellular Damage.- Stress and BDNF.- Co-Administration of a Phosphodiesterase Inhibitor and the Response to Selective Norepinephrine Reuptake Inhibitor.- Conclusion.- References.- Postreceptor Signal-Transduction Systems as Potential Targets of Lithium.- Lithium and Postreceptor Signal-Transduction.- Phosphoinositide Metabolism.- Adenylyl Cyclase System.- G Proteins.- Protein Phosphorylation and Gene Expression.- Conclusion.- References.- Participation of Cytoskeletal Elements in Neuronal Signal Transduction: New Insight into the Molecular Basis of Antidepressant Action.- Tubulin, G Proteins, and Adenylyl Cyclase Signal Transduction.- Tubulin - G Protein Interaction.- Cytoskeletal Elements and Antidepressant Drugs.- References.- In Vivo Investigations of Signal-Transduction Systems in Affective Disorders by Magnetic Resonance Spectroscopy.- Which Metabolites in Signal-Transduction Systems Can Be Measured by MRS?.- Neurotransmitters.- Second Messengers.- Phosphoinositide System.- Other Phospholipases.- Cyclic AMP.- Clinical Applications of MRS to the Study of Signal-Transduction Systems.- Phosphoinositide System.- Choline.- Lipids.- Conclusion.- References.