Cholinergic modulation by pedunculopontine tegmental nucleus to the brainstem respiratory neurons

• Grant number: 15/17182-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2016
• End date: February 28, 2017
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Thiago dos Santos Moreira
• Grantee: Janayna Dias Lima
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The proper functioning of the respiratory system depends of neural inputs originated in specific regions of the central nervous system (CNS). The retrotrapezoid nucleus (RTN) comprises a set of neurons located ventrally to the facial motor nucleus and has the ability to detect increased levels of CO2 in the plasma as well as the changes in pH, creating rapidly increase in respiratory activity; this phenomenon is called central chemoreception. Central chemoreceptors are neurons with chemosensitive features, which are able to detect changes in CO2 concentrations and plasma pH, promoting an appropriate adjustments in ventilation to restore blood gas homeostasis, among which the RTN receives prominent role. A recent work from our laboratory found that the RTN neurons are highly responsive to acetylcholine (Ach), by a muscarinic cholinergic receptors activation. It was also described that the Ach application in RTN increases the ventilation and blood pressure in unanesthetized male Wistar rats. We also demonstrated that a subset group of cholinergic neurons located in the pedunculopontine tegmental nucleus (PPT) project to RTN. According to the literature, stimulation of the PPT produces respiratory changes; however there is no evidence that indicates any direct relationship between PPT and RTN or with the neurons located in the pre-Botzinger complex. In this project, we intend to conduct a series of neuroanatomical and physiological experiment in order to identify the role PPT in the regulation of respiratory activity. (AU)