TAAR1 agonism blocks compulsive eating
Binge eating disorder (BED) is characterized by compulsive consumption of food within a short time period accompanied by loss of control over eating. Recent literature provides the basis for consideration of BED as an addiction-like disorder. In this study, we aimed to determine the effects of Trace Amine-Associated Receptor 1 (TAAR1) agonism on maladaptive forms of feeding behaviors. TAAR1 is an intracellular receptor preferentially expressed in monoaminergic cells, and involved in reward and motivation. For this purpose, we trained male rats to self-administer either a sugary, highly palatable diet (Palatable rats) or a chow diet (Chow rats) for 1 hour/day under a Fixed Ratio 1 (FR1) schedule of reinforcement. Following escalation and stabilization of binge-like eating of palatable food, we tested the effects of the TAAR1 agonist RO5256390 on i) binge-like eating and eating rate in the FR1 schedule, ii) compulsive eating in a light/dark conflict test, iii) food reward using a conditioned place preference test, and lastly iv) food seeking behavior using a second-order schedule of reinforcement. Results showed that RO5256390 blocked binge-like eating, compulsive eating, food reward, and food seeking behavior selectively in Palatable rats without affecting Chow controls’ performance. Results provide evidence that TAAR1 may be a potential pharmacological target for Binge Eating Disorder.