Les mécanismes neuronaux impliqués dans les troubles alimentaires

 

Elena Timofeeva

Centre de recherche de l'Institut univesitaire de cardiologie et de pneumologie de Québec

 

Domaine : neurosciences, santé mentale et toxicomanies

Programme chercheurs-boursiers - Senior

Concours 2014-2015

In my laboratory we study food intake regulation by the brain and why does eating sometimes come out of the control and how do eating disorders develop. More specifically, during the next four years our research projects will investigate the neuronal mechanisms of development of binge eating. To address this problem, we generated a rat model of binge-like eating which was developed by chronic stress, repeated dieting (food restriction) and refeeding on palatable food.

This model has revealed that in the normal state feeding is under control of the homeostatic brain centers, however, the development of binge eating displaced food intake control to the brain regions involved in reward and addiction. The present program will investigate the mechanisms of this dynamical shift of the neuronal activity. Another piece of the puzzle is that chronic stress frequently triggers binge eating of palatable food in contrast to acute stress that normally decreases appetite. The present project will study how chronic stress alters the neuronal mechanisms which instead of the anorectic reaction trigger episodes of binge eating. Another puzzling question that will be investigated in the present study: why is the rate of incidence of eating disorders about 10 times higher for women compared to men? To study this problem, we developed a rat model in which chronic stress and repeated food restriction trigger overeating and increased body weight gain in female but not male rats.

This model showed possible implication of orexigenic neuropeptide relaxin-3 in chronic stress-induced overeating in females. In general, this research program will generate new knowledge about the neuronal mechanisms related to eating disorders and propose new therapeutic solutions.