Characterization of branchial neuroepithelial cells (putative O2 chemoreceptors) and c-Fos expression in central areas after hypoxic exposure in the African catfish (Clarias gariepinus)

• Grant number: 13/12408-4
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2013
• End date: February 29, 2016
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Francisco Tadeu Rantin
• Grantee: Francisco Tadeu Rantin
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated researchers: Luciane Helena Gargaglioni Batalhão

Abstract

In fish, environmental hypoxia induces physiological adjustments detected mainly by branchial O2 chemoreceptors. Neuroepithelial cells (NECs) found in fish gill arches are morphologically similar to the mammalian chemoreceptors, being suggested as the putative O2-sensitive sites. The present study aims to determine the NECs distribution in the gas exchanging organs of the African catfish Clarias gariepinus. Fish will be maintained in 1000 L tanks with constant aeration (PwO2 ~ 140 mmHg) and temperature (25 ± 1 oC) and daily fed. The studies will be conduct by means of immunohistochemistry techniques, characterizing the NECs and the presence of the neurotransmitter serotonin (5-HT), cytoplasmic dense core vesicles (DCVs) and innervation patterns. Furthermore, fish will be submitted to acute hypoxia exposure in order to detect NECs alterations provoked by this stimulus. Concomitantly, the encephala will be analyzed by means of the c-fos protein expression to detect the central areas activated by acute hypoxia exposure. (AU)