The Influence of ΔFosB in the Nucleus Accumbens on Natural Reward-Related Behavior

The transcription factor deltaFosB (Delta FosB), induced in nucleus accumbens (NAc) by chronic exposure to drugs of abuse, has been shown to mediate sensitized responses to these drugs. However, less is known about a role for Delta FosB in regulating responses to natural rewards. Here, we demonstrate that two powerful natural reward behaviors, sucrose drinking and sexual behavior, increase levels of Delta FosB in the NAc. We then use viral-mediated gene transfer to study how such Delta FosB induction influences behavioral responses to these natural rewards. We demonstrate that overexpression of Delta FosB in the NAc increases sucrose intake and promotes aspects of sexual behavior. In addition, we show that animals with previous sexual experience, which exhibit increased Delta FosB levels, also show an increase in sucrose consumption. This work suggests that Delta FosB is not only induced in the NAc by drugs of abuse, but also by natural rewarding stimuli. Additionally, our findings show that chronic exposure to stimuli that induce Delta FosB in the NAc can increase consumption of other natural rewards.