FIGHTING UNHEALTHY EATING HABITS: THE PROTECTIVE ROLE OF ENVIRONMENT ON JUVENILE OBESITY

Obesity is a major global health concern and is mainly driven by excessive craving and eating of high-fat and high-sugar foods. As rates of obesity are increasing, particularly in children and teens, it is essential we understand the brain processes that promote craving and overeating. Brief episodes of cognitive and physical stimulation through games and exercise reduce food cravings in humans. In mice, we model this through environmental enrichment (EE) using spacious cages with toys, objects to interact with and tunnels, running wheels and varied nesting materials. These methods represent a promising, non-pharmacological, translational therapeutic approach. Using behavioural procedures and brain tissue analyses, we are the first to examine the effect of EE in mice exposed to unhealthy diets during adolescence and to quantify changes in the endocannabinoid system, a central actor in the control of feeding which undergoes large scale changes during adolescence. We found that adolescent sugar exposure decreases cue-induced approach for sugar pellet rewards in Pavlovian conditioning. Brief (24 hr) exposure to EE impairs this approach behaviour in control mice, reducing food seeking. In contrast, EE restores the suppressed approach seen in adolescent sucrose-exposed mice. We are now exploring the neural mechanisms of these EE effects, investigating the dopamine and endocannabinoid systems.