Sexually dimorphic effects of prenatal cocaine on adult sexual behavior and brain catecholamines in rats

Abstract

Exposure to cocaine in utero (10 mg/kg twice a day on days 11–18 of gestation) differentially altered adult sexual behavior, brain catecholamine levels and perhaps open field activity in male and female rats. Female rats exposed to cocaine were significantly inhibited in their sexual behavior when compared to saline-exposed controls. In contrast, males exposed prenatally to cocaine exhibited normal or even facilitated sexual behavior. In particular, the significantly shorter post-ejaculatory intromission intervals displayed by cocaine-exposed males indicated that these animals might have enhanced sexual arousal or motivation. In tests for open field activity, males consistently showed higher levels of rearing behavior than females. Prenatal cocaine tended to reduce rearing in females, but this effect was not significant. Cocaine-exposed male rats had significantly higher norepinephrine and dopamine levels in the preoptic area than saline-exposed controls, whereas cocaine did not affect catecholamine content in male hypothalamus, striatum, cortex or cerebellum. Cocaine- and saline-exposed females had similar catecholamine levels in all brain regions. These results suggest that exposure of developing animals to modest doses of cocaine during mid to late gestation results in long-lasting, sexually dimorphic alterations of adult sexual behavior and brain catecholamines in rats.