Study of GABAA receptors on the sleep-like behavior in Coturnix japonica (Temminck Schlegel, 1849) (Galliformes: Aves).
The present study was carried out to investigate the influence of GABAA signaling on sleep-like behaviors through systemic administration of bicuculline and picrotoxin (GABAA antagonists) and thiopental (an allosterical modulator). A thiopental (20 mg/kg) injection increased the eye closure frequency compared to the control group. The birds quickly became sleepy with a low frequency of early behavioral stages, such as rapid oral movement (ROM), feather ruffling and blinking. A bicuculline administration (1 and 4 mg/kg) did not modify the frequency of feather ruffling, ROM, eye closure or blinking responses. A lower dose of picrotoxin (2 mg/kg) stimulated an active awakening status, while an intermediate dose (4 mg/kg) elicited a moderate awakening status, which was associated with an increase in the frequency of ROM, blinking and eye closure. At the higher dose (8 mg/kg), the birds exhibited thermoregulatory-like behaviors and convulsions immediately after the injection. Interestingly, picrotoxin (4 mg/kg) intensified the eye closures when given in combination with thiopental (20 mg/kg). Both barbiturate and picrotoxin-induced sleep-like responses have the same behavioral neuropharmacological properties, conceivably because they are correlated with action at an identical site on the GABAA receptor.
Polo
Patrícia Almeida
PA
Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR465, Km07, Seropédica, RJ 23890-000, Brazil.
Mecawi
André Souza
AS
Lapa
Marco Antonio Pires Camilo
MA
Côrtes
Wellington Silva
WS
Reis
Luis Carlos
LC
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001640:Bicuculline / Q000494:pharmacology; D003370:Coturnix; D004305:Dose-Response Relationship, Drug; D018682:GABA Agents / Q000494:pharmacology; D008297:Male; D010852:Picrotoxin / Q000494:pharmacology; D011963:Receptors, GABA-A / Q000378:metabolism*; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D013874:Thiopental / Q000494:pharmacology
D001640:Bicuculline; D018682:GABA Agents; D010852:Picrotoxin; D011963:Receptors, GABA-A; D013874:Thiopental