The effect of MC3/4 receptor agonist and antagonist injections into the ventral tegmental area on motivated food behavior

Obesity has become a serious problem in the US. According to the Centers for Disease Control and Prevention, currently ~70% of the US population can be considered overweight or obese. In order to tackle the issue of obesity, it is very important to identify the neural mechanisms that regulate feeding. This will aid us to combat the bigger issue of obesity. The Arcuate nucleus contains two sets of neurons that play an important role in the control of feeding, while the mesolimbic dopamine system plays a major role in most reward based behavior including the reward-related responses to drugs and food. There have been increasing evidence of the melanocortin system interacting with the mesolimbic dopamine system in mediating hedonic feeding. In these studies we tested whether injecting the melanocortin receptor antagonist and agonist, SHU 9119 and MTII, in the ventral tegmental area (VTA) has an effect on reward-based food intake. MTII decreased reward based food intake while SHU9119 affected motivated food intake behavior at a high concentration. Overall, these studies increase our understanding the role of αMSH in the VTA on motivated food reward behavior. INDEX WORDS: MC3R, MC4R, motivated food intake, VTA, dopamine, MSH The effect of MC3/4 receptor agonist and antagonist injections into the ventral tegmental area on motivated food behavior