ΔJunD overexpression in the nucleus accumbens prevents sexual reward in female Syrian hamsters

Motivated behaviors, including sexual experience, activate the mesolimbic dopamine system and produce long-lasting molecular and structural changes in the nucleus accumbens. The transcription factor Delta FosB is hypothesized to partly mediate this experience-dependent plasticity. Previous research in our laboratory has demonstrated that overexpressing Delta FosB in the nucleus accumbens of female Syrian hamsters augments the ability of sexual experience to cause the formation of a conditioned place preference. It is unknown, however, whether Delta FosB-mediated transcription in the nucleus accumbens is required for the behavioral consequences of sexual reward. We therefore used an adeno-associated virus to overexpress Delta JunD, a dominant negative binding partner of Delta FosB that decreases Delta FosB-mediated transcription by competitively heterodimerizing with Delta FosB before binding at promotor regions on target genes, in the nucleus accumbens. We found that overexpression of Delta JunD prevented the formation of a conditioned place preference following repeated sexual experiences. These data, when coupled with our previous findings, suggest that Delta FosB is both necessary and sufficient for behavioral plasticity following sexual experience. Furthermore, these results contribute to an important and growing body of literature demonstrating the necessity of endogenous Delta FosB expression in the nucleus accumbens for adaptive responding to naturally rewarding stimuli.