GABAergic effects of reserpine following chronic treatment.

Reserpine-induced depression has been used as an animal model to screen for antidepressant agents. Chronic (14-day) treatment with reserpine resulted in a significant increase in beta-adrenergic receptor binding in the cerebral cortex and the hippocampus, which was partially prevented by chronic treatment with either the antidepressant imipramine, the GABA-A agonist THIP or, the GABA-B agonist baclofen. Chronic treatment with reserpine also significantly increased 3H-GABA receptor binding, which was partially prevented by chronic treatment with either imipramine or THIP. Both subchronic and chronic administration of reserpine resulted in a decrease in GABA concentrations in the cerebral cortex and hippocampus. These data demonstrate the effect of reserpine treatment on the GABA-ergic system, and add further support for a functional coupling between the noradrenergic and GABA-ergic systems, which may be important for the mechanism of action of antidepressant agents.