title: Postnatal development of orexin-A and orexin-B like immunoreactivities in the Eastern grey kangaroo (Macropus giganteus) hypothalamus.
abstract: The Eastern grey kangaroo (Macropus giganteus) is a marsupial, which is born in an extremely undeveloped state and has a long suckling period in the mother's pouch. In the present study, we examined the immunoreactivities of orexin-A (OXA) and orexin-B (OXB) in the hypothalamus of the Eastern grey kangaroo during the preweaning period, postweaning period and adulthood. In the preweaning period, only a few OXA- and OXB-like immunoreactive (LI) neurons and fibers were present and the intensity of staining was very weak. In the postweaning period, there was a pronounced increase in the numbers of OXA- and OXB-LI neurons and fibers and the intensity of the immunoreactivity was considerably stronger in comparison to the preweaning period. In the adult, the numbers of OXA- and OXB-LI neurons and fibers appeared to be slightly increased and the intensity was slightly stronger in comparison to the postweaning period. At all time periods, the distributions of OXA- and OXB-LI neurons was similar. The postnatal development of hypothalamic orexin neurons may be associated with developmental changes, including feeding behavior.
authors.affiliation: Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan. y-yuki@med.uoeh-u.ac.jp
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McKinley
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Nakazato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Akira
authors.initials: A
authors.lastname: Shirahata
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ueta
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007031:Hypothalamus / Q000254:growth & development / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D007614:Macropodidae / Q000254:growth & development / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins