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 t o modify NPY-stimulated eating. This suggests that 5-HT2A/2C receptor modulation of NPY feeding within the hypothalamus is localized to the PVN.