Anatomical characterization of the source of inhibition of neurons in the nucleus retrotrapezóide involved in the control of active expiration

• Grant number: 14/23418-3
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): May 01, 2016
• Effective date (End): November 30, 2018
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal researcher: Ana Carolina Thomaz Takakura
• Grantee: Josiane do Nascimento Silva
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The control of the respiratory system is accomplished by neurons located in the medulla and pons. The bulb has regions involved in respiratory control located in the ventral respiratory column and dorsal respiratory column. The retrotrapezóide nucleus (RTN) is a region located in the ventral respiratory column bulb. The region contains the RTN chemoreceptor neurons that express the transcription factor PHOX2B and respond to hypercapnia and hypoxia; For this reason, this region is considered a strong candidate to be a central chemoreceptors (Mulkey et al, 2004; Dubreuil et al, 2008; Guyenet et al, 2009). Experiments described in the literature have shown the importance of the RTN in inspiration (Dobbins and Feldman, 1994; Takakura et al, 2006; Guyenet et al, 2008) and also in active expiration (E2 phase) (Janczewski and Feldman, 2006a, 2006b; Abdala et al, 2009; Pagliardini et al, 2011; Moraes et al, 2014). However, data in the literature suggest that there is a RTN synaptic inhibition for withdrawing the active expiration and that this inhibition is removed during a situation requiring the activation of this E2 phase of breathing, for example (Pagliardini et al, 2011) during exposure to a situation of hypercapnia, hypoxia, or physical activity. However, until now, no one knows the source of this inhibition for the RTN neurons that control active expiration. Therefore, the main objective of this project is to investigate the anatomical and functional form, the location of the source of inhibition for the RTN and the phenotype of neurons involved in this projection.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, JOSIANE DO N.; OLIVEIRA, LUIZ M.; SOUZA, FELIPE C.; MOREIRA, THIAGO S.; TAKAKURA, ANA C. GABAergic neurons of the medullary raphe regulate active expiration during hypercapnia. Journal of Neurophysiology, v. 123, n. 5, p. 1933-1943, MAY 2020. Web of Science Citations: 0.

SILVA, JOSIANE N.; OLIVEIRA, LUIZ M.; SOUZA, FELIPE C.; MOREIRA, THIAGO S.; TAKAKURA, ANA C. Distinct pathways to the parafacial respiratory group to trigger active expiration in adult rats. AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY, v. 317, n. 3, p. L402-L413, SEP 2019. Web of Science Citations: 1.