Grant: Operating Grant

The rate of incidence of stress-induced binge eating and prevalence of obesity associated with this disorder is approximately10 times higher for women compared to men. The underlying neuronal basis of this sexual dimorphism is not yet known. However, the causes triggering and precipitating eating disorders have become more evident. Thus, chronic stress and repeated food restriction have been identified as strong antecedents and relapse factors of binge eating. Repeated episodes of overeating increase the prevalence of obesity. To study the neuronal and molecular mechanisms of eating disorders in females, we have developed a rat model in which chronic stress and repeated food restriction trigger overeating and increase body weight in female but not male rats. Our results suggest that sex-specific regulation of brain expression of orexigenic neuropeptide relaxin-3 may be a cause of overeating and increased body weight in chronically stressed females. This research proposal is focused on the role of relaxin-3 in sex-specific regulation of food intake and body weight in female rats. The results of this project will help to understand why approximately 90% of individuals hospitalized for eating disorders are women, and will suggest pharmacological and neurogenetic therapeutic strategies.