Behavioral and metabolic effects of central injections of orexins/hypocretins in pigeons (Columba livia).
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.
da Silva
Eduardo Simão
ES
Department of Physiological Sciences, CCB, Federal University of Santa Catarina, 88049-900 Florianópolis SC, Brazil.
dos Santos
Thiago Viçoso
TV
Hoeller
Alexandre Ademar
AA
dos Santos
Tiago Souza
TS
Pereira
Gustavo Vieira
GV
Meneghelli
Cristiane
C
Penzlin
Ana Isabel
AI
Pezlin
Ana Isabel
AI
dos Santos
Murilo Marcos
MM
Faria
Moacir Serralvo
MS
Paschoalini
Marta Aparecida
MA
Marino-Neto
José
J
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
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins