title: Study of GABAA receptors on the sleep-like behavior in Coturnix japonica (Temminck Schlegel, 1849) (Galliformes: Aves).
abstract: 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.
authors.affiliation: Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, BR465, Km07, Seropédica, RJ 23890-000, Brazil.
authors.forename: Patrícia Almeida
authors.initials: PA
authors.lastname: Polo
authors.forename: André Souza
authors.initials: AS
authors.lastname: Mecawi
authors.forename: Marco Antonio Pires Camilo
authors.initials: MA
authors.lastname: Lapa
authors.forename: Wellington Silva
authors.initials: WS
authors.lastname: Côrtes
authors.forename: Luis Carlos
authors.initials: LC
authors.lastname: Reis
mesh_terms: 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
chemical_list: D001640:Bicuculline; D018682:GABA Agents; D010852:Picrotoxin; D011963:Receptors, GABA-A; D013874:Thiopental