Postinspiratory complex and retrotrapezoid nucleus: role of cholinergic signaling

• Grant number: 16/23077-7
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): February 01, 2017
• Effective date (End): January 31, 2018
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal researcher: Thiago dos Santos Moreira
• Grantee: Cleyton Roberto Sobrinho
• Supervisor abroad: Daniel Kent Mulkey
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: University of Connecticut (UCONN), United States
• Associated to the scholarship: 15/12827-2 - Acetylcholine and ventilation: Modulation by cholinergic inputs from pedunculopontine tegmental nucleus to the retrotrapezoid nucleus, BP.PD

Abstract

The retrotrapezoid nucleus (RTN) contains neurons that regulate breathing in response to changes in tissue CO2/H+ (central chemoreceptors), increasing the inspiration and generating active expiration. Recently, a new rhythm structure breathing-related has been identified in the medulla, a cluster compose by neurons that co-expressing Glutamate and Acetylcholine which displays autonomous bursts always after the inspiratory phase: The postinspiratory complex (PiCO). Additionally, photostimulation of cholinergic PiCO neurons elicit a postinspiratory burst. We had reported that cholinergic signaling act on muscarinic M1/ M3 receptors in the RTN chemosentive neurons. Ongoing studies from our lab were able to detect a conspicuous number of cholinergic neurons in close apposition of the PiCO area with projections to the RTN (unpublished data). However, the physiological significance of cholinergic signaling at RTN site have not been completely elucidate. Based on previous and present data, important issues emerge: Which is the physiological relevance of cholinergic input to the RTN-chemoreceptors neurons? Could the RTN participate on the postinspiratory activity? Is the cholinergic signaling in the RTN involved in this process? Considering the well described cholinergic input to RTN and the importance of this nucleus to the breathing control, our main aim is to better investigate the physiological role of the cholinergic input to the RTN region and a possible relationship between RTN and the PiCO region in the postinspiratory phase of the breathing cycle. (AU)