Over 1 billion people worldwide are overweight and over 300 million are obese. The hypothalamus is the main centre of the brain controlling appetite, primarily the arcuate nucleus (ARC), having in composition orexigenic neurons coexpressing NPY/AgRP (neuropeptide Y/Agouti gene-related protein) and anorexigenic ones with POMC/CART (proopiomelanocortin /cocaine- and amphetamine-related transcript). There are projections from the ARC to other hypothalamic nuclei, as well as to mesolimbic system and the cerebral cortex. The brainstem (the dorsal vagal complex) receives vagal afferents from the gut and has projections to the hypothalamus, particularly the ARC. The hypothalamus and the brainstem have direct access to circulating gut hormones (ghrelin, CCK, GLP-1, oxyntomodulin, PYY, pancreatic polypeptide), to insulin from endocrine pancreas, to adipokines (leptin etc.) secreted by adipose tissue – correlated with satiety, adiposity and caloric intake regulation. Identifying in the future of potential therapeutic targets for the treatment of obesity relies on fully understanding these pathways and peptides.
Keywords: hypothalamus, brainstem, orexigens, anorexigens, gut hormones and adipokines