4 aminobutyric acid 4 aminobutyric acid h 3 Animal Binding Sites Cell Membrane Cerebral Cortex Cerebral cortex Circadian Rhythm Dose-Response Relationship, Drug GABA binding Injections, Subcutaneous Kinetics Male Melatonin Nerve Crush Pineal Gland Pineal gland Rats Rats, Inbred Strains Subcellular Fractions Superior cervical ganglion Support, Non-U.S. Gov't animal cell autonomic nervous system brain cortex central nervous system drug efficacy drug receptor binding endocrine system gamma-Aminobutyric Acid