MALE-RAT SEXUAL-BEHAVIOR INDUCES CHANGES IN [H-3] FLUNITRAZEPAM BINDING

The effect of male rat sexual behavior on the binding of [H-3]-flunitr azepam (FNP) in frontal cortex, hypothalamus and hippocampus was measu red. The groups included were: (A) control (no sexual experience) hand led males; (B) male rats sacrificed 24 h after their fifth mating expe rience; (C) males sacrificed 48 h after their fifth mating experience; (D) male rats sacrificed after 5 intromissions during the sixth matin g experience; and (E) males sacrificed immediately after the first eja culation during the sixth mating experience. Relative to handled contr ols, significant decreases in maximal [H-3]-FNP binding (B(max)) were observed in frontal cortex and hippocampus of animals sacrificed after 5 intromissions and in frontal cortex of rats sacrificed 24 h after t he last mating experience. Relative to males sacrificed after 5 introm issions, males sacrificed immediately after ejaculation exhibited a ra pid increase in B(max) in frontal cortex and hippocampus. No between-g roup differences in K(d) for [H-3]-FNP were noted, and sexual experien ce had no effect on the B(max) of [H-3]-FNP in the hypothalamus.