Hypocretin I (also referred to as orexin A) administered into the lateral hypothalamus (LH) stimulates feeding in rats. We undertook the present study to determine the brain regions activated by LH administration of hypocretin I. Hypocretin I administered into the LH significantly elevated cFos-immunoreactivity in the lateral septal area, the central nucleus of the amygdala, the shell of the nucleus accumbens, the bed nucleus of the stria terminalis, the LH, the posterior and dorsomedial hypothalamus, the perifornical, arcuate and paraventricular nuclei and the nucleus of the solitary tract. These data indicate that LH hypocretin I communicates with other key energy regulatory sites within the hypothalamus, the limbic region and the hindbrain, and suggest that these areas are important in the feeding-stimulatory actions of hypocretin I.
1Veterans Affairs Medical Center, Research Service (151) Minneapolis, MN 55417, USA
2Minnesota Obesity Center, One Veterans Drive, Research Route 151, Minneapolis, MN 55417, USA
3Departments of Food Science and Nutrition, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA
4Departments of Psychiatry, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA
5Departments of Medicine, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA
6Corresponding Author and Address: Catherine M. Kotz, Veterans Affairs Medical Center, Research Service (151) Research Route 151, Minneapolis, MN 55417, USA
Acknowledgements: This work was supported by the Department of Veterans Affairs, the Minnesota Obesity Center and Knoll Pharmaceutical Company in conjunction with the Weight Risk Investigators Study Council.
Received 21 September 1999; accepted 20 October 1999