title: Behavioral and metabolic effects of central injections of orexins/hypocretins in pigeons (Columba livia).
abstract: In the present study, the acute behavioral and ingestive effects of ICV injections of mammalian orexin-A (ORXA; vehicle, 0.2, 0.6 or 2 nmol) and of orexin-B (ORXB; vehicle, 0.2, 0.6 or 2 nmol), as well as possible long-term effects (through 24 h of continuous intake monitoring after 0.6 nmol of ORXA or ORXB) of these treatments in food/water intake and in blood levels of metabolic fuels (free fatty acids and glucose, after 0.2 or 0.6 nmol of ORXA) were examined in adult male pigeons. Both ORXA and ORXB treatments failed to produce acute (1-3 h) or long-term effects on feeding and drinking behaviors, and did not change blood free fatty acids and glucose 15 and 30 min after treatments, as compared to vehicle-treated animals. However, ORXA (but not ORXB) treatments evoked a dose-related, intense increase in exploratory behaviors, associated to reduced time spent in alert immobility and sleep-typical postures. These data substantiate the lack of orexigenic effects of ORXs in avian species, and suggest that an important role in vigilance control may represent a conserved functional attribute of orexinergic circuits in vertebrates.
authors.affiliation: Department of Physiological Sciences, CCB, Federal University of Santa Catarina, 88049-900 Florianópolis SC, Brazil.
authors.forename: Eduardo Simão
authors.initials: ES
authors.lastname: da Silva
authors.forename: Thiago Viçoso
authors.initials: TV
authors.lastname: dos Santos
authors.forename: Alexandre Ademar
authors.initials: AA
authors.lastname: Hoeller
authors.forename: Tiago Souza
authors.initials: TS
authors.lastname: dos Santos
authors.forename: Gustavo Vieira
authors.initials: GV
authors.lastname: Pereira
authors.forename: Cristiane
authors.initials: C
authors.lastname: Meneghelli
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Penzlin
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Pezlin
authors.forename: Murilo Marcos
authors.initials: MM
authors.lastname: dos Santos
authors.forename: Moacir Serralvo
authors.initials: MS
authors.lastname: Faria
authors.forename: Marta Aparecida
authors.initials: MA
authors.lastname: Paschoalini
authors.forename: José
authors.initials: J
authors.lastname: Marino-Neto
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D010856:Columbidae / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D007276:Injections, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D000068797:Orexins; D012890:Sleep / Q000187:drug effects
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins