Differential distribution of orexin-A and orexin-B immunoreactivity in the rat brain and spinal cord

• Published in: Peptides (New York, N.Y. : 1980) Vol. 20; no. 12; pp. 1455 - 1470
• Main Authors: Cutler, David J, Morris, Richard, Sheridhar, Vimal, Wattam, Trevor A.K, Holmes, Stephen, Patel, Sara, Arch, Jonathan R.S, Wilson, Shelagh, Buckingham, Robin E, Evans, Martyn L, Leslie, Ron A, Williams, Gareth
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-1999
• Subjects: Amino Acid Sequence; Animals; Antibody Specificity; Brain - metabolism; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Carrier Proteins - physiology; Eating - physiology; Feeding; Hypocretin; Hypothalamus; Hypothalamus - metabolism; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Lateral hypothalamic area; Male; Molecular Sequence Data; Neuropeptides - chemistry; Neuropeptides - metabolism; Neuropeptides - physiology; Orexin-A; Orexin-B; Orexins; Rats; Rats, Wistar; Spinal cord; Spinal Cord - metabolism; Tissue Distribution; Immunohistochemistry; Lateral hypothalamic area; Spinal cord; Orexin-A; Orexin-B; Hypothalamus; Hypocretin; Feeding
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(99)00157-6

The orexins are recently identified appetite-stimulating hypothalamic peptides. We used immunohistochemistry to map orexin-A and orexin-B immunoreactivity in rat brain, spinal cord, and some peripheral tissues. Orexin-A- and orexin-B-immunoreactive cell bodies were confined to the lateral hypothalamic area and perifornical nuclei. Orexin-A-immunoreactive fibers were densely distributed in the hypothalamus, septum, thalamus, locus coeruleus, spinal cord, and near the ventricles, but absent from peripheral sites investigated. In contrast, orexin-B-immunoreactive fibers were distributed sparsely in the hypothalamus. Orexin cells are strategically sited to contribute to feeding regulation, but their widespread projections suggest that orexins have other physiological roles.