Figure 1.
Hypothalamic control of energy metabolism. The brain integrates metabolic signals (leptin, insulin, ghrelin, PYY3–36) from peripheral tissues such as pancreas, adipose tissue, and gut. In the brain, specialized neuronal networks coordinate adaptive changes in food intake and energy expenditure. Neuropeptide Y/agouti-related protein (AgRP)-gamma aminobutyric acid (GABA) and proopiomelanocortin (POMC)-Cocaine and amphetamine-related transcript (CART) producing neurons in the hypothalamic arcuate nucleus primarily sense the body energy state. These neurons project to other second order neurons to control the regulation of energy balance. Abbreviations: ARC, arcuate nucleus; PYY3-36, peptide YY3-36; CK, cholecystokinin; GLP-1, glucagon-like peptide-1; OXM, oxyntomoduline; PP, pancreatic polypeptide.