Oral Presentation Australian and New Zealand Obesity Society Annual Scientific Conference 2024

Binge eating in adolescent rats (#53)

Simone Rehn 1 , Joanne Gladding 1 , Laura Bradfield 1 , Michael Kendig 1
  1. University of Technology Sydney, Ultimo, NSW, Australia

Binge eating involves eating large amounts of food in a short period of time and is associated with psychological distress, depressive symptoms, and obesity. Adolescence is a critical stage for the onset of binge eating disorder and is predictive of disordered eating and poor mental health in young adulthood. This highlights the need to investigate potential learning and neural mechanisms that drive the development of binge eating during adolescence and explain its persistence. Animal models of binge eating offer valuable insights into the causes and consequences of human binge eating, yet few have focused on adolescence. In our experiment, adolescent female rats were allocated to one of three feeding conditions: 1) standard chow only (Chow); 2) continuous access to a cafeteria diet and standard chow (Cafeteria); or 3) limited access to cafeteria diet and standard chow (Binge). Binge rats showed escalating food intakes across the four-week protocol such that their intakes were three times that of the Cafeteria and Chow rats by the end. Rats were then trained to lever press and tested for sensitivity to instrumental outcome devaluation as well as motivational changes using a progressive-ratio reinforcement schedule. Preliminary data suggests intact sensitivity to devaluation in all groups, suggesting no alteration to goal-directed action control, but lower lever press responding in Caf-fed rats, indicative of reduced motivation. Neuroinflammatory markers within the hippocampus were assessed post-mortem.