Grant: CIHR New Investigator

One last morsel of food remains on your dinner plate. You hesitate but in spite of feeling full you manage to eat the last bite. Your plate is clean and your hunger is satisfied. Without a conscious thought of eating anything more your eyes glance over the dessert menu. The anticipation of the novel sensory experience presented by the tasty treats makes you perk-up, and before you know it you are devouring another mouthful. The rewarding effects of palatable foods can drive us to eat not only when we are hungry and need to replenish energy stores but also in states of satiety when energy is replete. Which mechanisms in the brain are responsible for motivating us to consume foods rich in fat and sugar? Our work explores the neural pathways that underlie motivation for food and other behaviours that regulate body weight. Circulating hormones like leptin target mesolimbic neural circuitry to influence feeding in part by affecting dopamine, a neurotransmitter playing a fundamental role in motivation and reward. On the one hand, our goal is to discover how hormonal and nutrient signals influence dopamine signalling and food-motivated behavior. On the other hand, our work aims to determine how eating a palatable, high-fat diet over time causes adaptations in brain reward circuitry that promote over-eating and negative mood states. As we are confronted with the health, social and economic consequences of obesity and nutritionally-related illnesses, elucidating the mechanisms that regulate motivation for high-fat and -sugar food remains an important goal.