INCREASE IN SEROTONIN 1A RECEPTORS IN THE DENTATE GYRUS AS REVEALED BY AUTORADIOGRAPHIC ANALYSIS FOLLOWING REPEATED ELECTROCONVULSIVE SHOCK BUT NOT IMIPRAMINE TREATMENT

The effects of repeated treatment with electroconvulsive shock (ECS) and imipramine on [H-3]8-OH-DPAT binding to serotonin(1A) (5-HT1A) receptors in the rat brain were studied by quantitative autoradiographic analysis. A large number of binding sites for [H-3]8-OH-DPAT were observed in the hippocampus, especially the dentate gyrus, CA(1)+CA(2) field, dorsal raphe nucleus and septum. Repeated treatment with ECS, but not repeated imipramine treatment, significantly increased [H-3]8-OH-DPAT binding sites in the dentate gyrus. These results suggest that the increase in [H-3]8-OH-DPAT binding sites in the dentate gyrus may be important in ECS therapy for depressive illness.