Research has highlighted the importance of reward-based processes in binge eating (BE). However, both increased and decreased activation have been observed in reward related brain regions for BE. Differences may be similar to addiction research, where the reward system is initially hyper-responsive at early stages of use, but becomes hypo-responsive with prolonged drug/alcohol use. This study was the first to examine differences in reward system responsivity at early versus chronic BE stages.
Using an animal model, Sprague-Dawley female rats were identified as BE prone (BEP) or BE resistant (BER) and randomly assigned to an early or chronic stage group. Neural activation (via Fos) was quantified in the nucleus accumbens core (NAC) and shell (NAS).