Neuroendocrine Control of Body Energy Homeostasis

The brain integrates the response to a variety of signals of energy need and availability to match food intake with energy expenditure, thereby maintaining body weight stability. Early work with rodent models with disrupted energy balance (generally obesity) identified many hypothalamic genes and signaling pathways that impact energy homeostasis. More recent studies have identified hindbrain circuits that interact with peripheral metabolic signals and hypothalamic circuits to impact energy balance. Feeding, signals of energy utilization, and hormonal signals of energy stores (such as leptin) modulate gene expression and neurotransmission in specialized circuits within the hypothalamus and brainstem to control food intake. While many of these circuits also control energy expenditure, the effects on body weight that arise from alterations in energy expenditure are generally more modest than the effects of produced by changes in feeding. Although most of the mechanistic work that defined the systems that control energy balance utilized rodent models, these systems have human orthologs whose disruption produces phenotypes comparable to those observed in rodents, confirming their conserved function. For complete coverage of all related areas of Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG .