Fos expression in feeding-related brain areas following intracerebroventricular administration of orphanin FQ in rats

While the influence of orphanin FQ (OFQ) on the regulation of food intake h as been substantiated, Little is known about feeding-related brain regions that mediate OFQ-induced feeding. To further investigate this, we injected OFQ intracerebroventricularly and evaluated c-Fos immunoreactivity in brain areas thought to be involved in the regulation of food intake. Altered c-F os expression as a consequence of OFQ injection was observed in the nucleus of the solitary tract, paraventricular nucleus of the hypothalamus, suprao ptic nucleus, central nucleus of amygdala, lateral septal nucleus and later al habenular nucleus. Presumably, OFQ modulates food ingestion through its action on these brain regions, most probably by activating feeding signals as well as suppressing satiety mechanisms. (C) 2000 Published by Elsevier S cience B.V. All rights reserved.