Participação da neurotransmissão orexinérgica nas respostas respiratórias à hipercarbia e hipóxia em sapos

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Fonseca, Elisa Maioqui
Orientador(a): Batalhão, Luciane Helena Gargaglioni lattes
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal de São Carlos
Programa de Pós-Graduação: Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas - PIPGCF
Departamento: Não Informado pela instituição
País: BR
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: https://repositorio.ufscar.br/handle/20.500.14289/1375
Resumo: The hypocretin or orexin A plays an important role in the modulation of respiratory control in mammals, but there are no data available for the role of Orexins in the peripheral and central chemoreception of non-mammalian vertebrates. Thus, the present study was designed to evaluate the location of orexinergic neurons in toads (Rhinella schneideri). In addition, we investigate if the orexinergic system of this species is important to hypoxic (5% O2 and N2 for balance) and hypercarbic (5% CO2, 21% O2 and N2 for balance) drive to breath. We assessed the role of the orexinergic system on respiratory responses by using intracerebroventricular injection of SB-334867 (orexin A receptor antagonist) during the light and the dark phase. Our results demonstrated that orexinergic neurons of Rhinella schneideri are located in the suprachiasmatic nucleus of diencephalon. Additionally, the injection of the orexin antagonist attenuated the ventilatory response to hypercarbia during the dark phase by acting on tidal volume and breathing frequency, while in the light phase, there was an attenuation in the ventilatory response to hypoxia by acting just in the tidal volume. We conclude that central orexin A contributes to hypercarbic and to hypoxic chemoreflex in toads Rhinella schneideri.