Stimulation of 5-HT2A/2C receptors within specific hypothalamic nuclei differentially antagonizes NPY-induced feeding

THE present study examined the impact of the 5-HT2A/2C agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) on the feeding-stimulant action of neuropeptide Y (NPY) injected into three hypothalamic sites, the paraventricular nucleus (PVN), the perifornical hypothalamus (PFH) and the ventromedial nucleus (VMH). Injections of NPY (100-200 pmol) into each region potentiated food intake. Pretreatment with DOI (5-20 nmol) into the PVN effectively suppressed feeding elicited by PVN NPY (100 pmol). In contrast, DOI injections into the PFH and VMH failed to modify NPY-stimulated eating. This suggests that 5-HT2A/2C receptor modulation of NPY feeding within the hypothalamus is localized to the PVN.