?FosB in the nucleus accumbens is critical for reinforcing effects of sexual reward.

ABSTRACT: Sexual behavior in male rats is rewarding and reinforcing. However, little is known about the specific cellular and molecular mechanisms mediating sexual reward or the reinforcing effects of reward on subsequent expression of sexual behavior. This study tests the hypothesis that ?FosB, the stably expressed truncated form of FosB, plays a critical role in the reinforcement of sexual behavior and experience-induced facilitation of sexual motivation and performance. Sexual experience was shown to cause ?FosB accumulation in several limbic brain regions including the nucleus accumbens (NAc), medial prefrontal cortex, ventral tegmental area and caudate putamen but not the medial preoptic nucleus. Next, the induction of c-Fos, a downstream (repressed) target of ?FosB, was measured in sexually experienced and naïve animals. The number of mating-induced c-Fos-immunoreactive cells was significantly decreased in sexually experienced animals compared with sexually naïve controls. Finally, ?FosB levels and its activity in the NAc were manipulated using viral-mediated gene transfer to study its potential role in mediating sexual experience and experience-induced facilitation of sexual performance. Animals with ?FosB overexpression displayed enhanced facilitation of sexual performance with sexual experience relative to controls. In contrast, the expression of ?JunD, a dominant negative binding partner of ?FosB, attenuated sexual experience-induced facilitation of sexual performance and stunted long-term maintenance of facilitation compared to green fluorescence protein and ?FosB overexpressing groups. Together, these findings support a critical role for ?FosB expression in the NAc for the reinforcing effects of sexual behavior and sexual experience-induced facilitation of sexual performance.

SUBMITTER: Pitchers KK 

PROVIDER: S-EPMC2970635 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature