Central Regulation of Appetite and Satiety Behavior

Abstract

To maintain constant body weight, an organism must be able to sense and counterbalance different aspects of energy homeostasis including food intake, energy stores, and energy expenditure. The central nervous system is responsible for integrating peripheral signals of food intake and adiposity, and transforming these signals into the conscious feelings of appetite or satiety. These function to modulate eating behavior. While there remains much to be understood about the central regulation of appetite and satiety behaviors, there is some insight into the effects of peripheral signals on central networks. This review will discuss the effects of peripheral signals on specific brain circuits as a means to understand the CNS regulation of eating behavior. First, the effects of gastrointestinal signals such as cholecystokinin and ghrelin on vagal signaling to the hindbrain will be examined as an example of the effect of autonomic signaling on eating behavior. Second, secreted factors which act directly on CNS neurons will be discussed, including the effects of leptin and insulin on arcuate-hypothalamic circuits which influence appetite and satiety behavior. Additional peripheral signals with anorexic or orexogenic effects will be outlined. Finally, higher order brain circuits will be examined, and the areas in which our understanding of the central regulation of feeding are as yet poorly understood will be highlighted.