Date of Award

Fall 8-20-2013

Degree Type


Degree Name

Master of Science (MS)



First Advisor

Aaron Roseberry

Second Advisor

Timothy Bartness

Third Advisor

Bingzhong Xue


Dopamine neurons of ventral tegmental area (VTA) are critical for control of homeostatic feeding, which relates to food intake necessary for maintaining normal physiological function. It also plays an important role in hedonic or ‘reward’ feeding. Alteration of mesolimbic dopamine pathways can change both baseline homeostatic and reward feeding. The melanocortin system of the hypothalamus also is important for control of feeding, and recently it has been shown that melanocortins can modulate the food intake by acting at dopamine pathways. Here, we tested whether injection of melanocortin receptor agonists into the VTA also affected reward feeding. Injection of melanocortin receptor agonists into the VTA decreased consumption of rewarding sucrose solutions (hedonic feeding), in addition to the expected reductions in normal chow intake (homeostatic feeding). These studies will give a better understanding of the mechanisms regulate acutely food intake and may have implication for treating obesity.