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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Orexin in the toad Rhinella schneideri: The location of orexinergic neurons and the role of orexin in ventilatory responses to hypercarbia and hypoxia

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Fonseca, Elisa M. [1] ; Dias, Mirela B. [2] ; Bicego, Kenia C. [1] ; Gargaglioni, Luciane H. [1]
Total Authors: 4
[1] Sao Paulo State Univ UNESP, FCAV, Dept Anim Morphol & Physiol, Jaboticabal, SP - Brazil
[2] Sao Paulo State Univ UNESP, Inst Biosci, Dept Physiol, Jaboticabal, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Respiratory Physiology & Neurobiology; v. 224, n. SI, p. 90-99, APR 2016.
Web of Science Citations: 3

Recent reports have suggested that orexins, also known as hypocretins, play an important role in the modulation of respiratory control in mammals, but there are no data available describing the role of the orexinergic system in the peripheral and central chemoreception of non-mammalian vertebrates. Therefore, the present study was designed to examine the localization of orexin-immunoreactive neurons in the brain of toads (Rhinella schneideri) and to investigate the contribution of orexin receptor-1 (0X(1)R) to the hypoxic and hypercarbic ventilatory responses of these animals during light and dark phases. Our results demonstrated that the orexinergic neurons of R. schneideri are located in the suprachiasmatic nucleus of the diencephalon. Additionally, the intracerebroventricular injection of SB-334867 (OX1R selective antagonist) attenuated the ventilatory response to hypercarbia during the dark phase by acting on tidal volume and breathing frequency, while during the light phase, SB-334867 attenuated the ventilatory response to hypoxia by acting on tidal volume only. We conclude that in the toad R. schneideri, orexinergic neurons are located in the suprachiasmatic nucleus and that OX1R contributes to hypercarbic and hypoxic chemoreflexes. (C) 2014 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 08/57712-4 - The National Institute of Comparative Physiological Research
Grantee:Augusto Shinya Abe
Support type: Research Projects - Thematic Grants
FAPESP's process: 12/19966-0 - Cardiorespiratory pattern and awake-sleep state in male and female rats exposed to fluoxetine during prenatal period
Grantee:Luciane Helena Gargaglioni Batalhão
Support type: Regular Research Grants