Modulation of CO¿-Induced Activation of NTS Neurons Receiving Orexinergic Projections in Normoxia and Hypercapnia

• Grant number: 25/10408-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: May 31, 2026
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: José de Anchieta de Castro e Horta Júnior
• Grantee: Mariana Souza Santos
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The regulation of pulmonary ventilation in response to hypercapnic stimuli involves a complex interaction between central and peripheral chemoreceptors. The nucleus of the solitary tract (NTS), a key region for integrating cardiorespiratory signals, receives afferent inputs from peripheral chemoreceptors and orexinergic projections from the hypothalamus. This project aims to investigate the activation of NTS neurons that receive orexinergic inputs during hypercapnic stimulation, comparing normoxia and hypercapnia conditions. The proposed hypothesis is that the differential activation of these neurons is modulated by the inhibition of the peripheral chemoreflex under hyperoxic conditions. Experiments will be conducted on Wistar rats using hypercapnic and normocapnic exposure models, followed by immunohistochemical analysis to identify Fos and orexins A and B in NTS neurons. The expected results include the functional characterization of orexinergic NTS neurons in ventilatory regulation and the role of orexinergic projections in integrating peripheral and central signals. (AU)