A schematic representation of the complex pathways involved in the regulation of food intake.

SNS, sympathetic nerve system; NTS, nucleus of the tractus solitarius; CCK, cholecystokinin; NPY, neuropeptide Y; AGRP, Agouti-related peptide; POMC, pro-opiomelanocortin; CART, cocaine-and amphetamine-regulated transcript; CRH, corticotropin-releasing hormone; TRH, thyrotropin-releasing hormone; MCH, melanin-concentrating hormone; PYY, peptide YY.