Role of microglial cell activation in response to increased levels of CO2 in the control of respiratory activity

• Grant number: 19/09718-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2019
• End date: October 31, 2020
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Thiago dos Santos Moreira
• Grantee: Vinicius Costa de Assis
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/23376-1 - Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity, AP.TEM

Abstract

Inflammation is defined as a biological response caused by numerous agents and is a key element in defense against infections. In the central nervous system, the main defense cell is microglia. Because of the elementary source of inflammatory factors, regulation of microglia may represent therapeutic potential for neuropsychiatric diseases and, when activated in the ventral respiratory column region, can cause an intensification of respiratory activity. The retrotrapezoid nucleus (RTN) is located between the facial motor nucleus and the ventrolateral surface of the bulb, extending from the caudal portion of the trapezoid body to the caudal region of the facial motor nucleus. These neurons are involved in central chemoreception, being highly sensitive to variations of carbon dioxide (CO2) and pH, and the generation of expiratory activity. The cells of the microglia act together with astrocytes responding to neural disorders. These astrocytes in turn release ATP when stimulated by increasing the CO2 or H + concentration, activating ventral respiratory column neurons, including RTN. However, there is no scientific data to date that elucidate a possible participation of the microglia cells in the same activity. From this information, it is important to investigate the connection between the selective activation of microglial cells in the region of the RNN and a possible increase in respiratory activity, as well as to understand and explain the mechanisms involved in this operation. The experiments to be elaborated in this project try to test this hypothesis and will be realized through neurophysiological and neuroanatomic techniques.