Influence of C1 neurons on the autonomic control carried out by the central action of insulin

• Grant number: 19/06482-3
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): September 01, 2019
• Effective date (End): April 30, 2021
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Vagner Roberto Antunes
• Grantee: Deborah de Paula Romeu
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Glucose is the most important energy substrate for the body, so it is vital to rigorously regulate blood glucose levels. Insulin is the main anabolic hormone that regulates glucose homeostasis, being responsible for glucose uptake and decrease of glycemia in the post-prandial period. In addition to its peripheral actions, insulin exerts a range of actions on the central nervous system, like modulating hepatic glucose production through the autonomic nervous system (ANS). Our laboratory has already demonstrated that centrally injected insulin can decrease glucose concentration of the hepatic vein (GCHV), by activation of the parasympathetic nervous system. However, this effect was not observed in spontaneously hypertensive rats (SHR), except when these animals underwent aerobic physical training or when there was pharmacogenetic stimulation (DREADD) of the dorsal motor nucleus of the vagus (DMV). DMV is the main parasympathetic nucleus, with preganglionic neurons that innervate the viscera (including liver and pancreas). This nucleus also as receives excitatory projections of the C1 group of the ventrolateral medulla - a group that is responsible for coordinating several mechanisms to maintain homeostasis in adverse situations. This project aims to investigate if C1 neurons participate in the autonomic control due to the central action of insulin in normotensive and hypertensive animals. In order to do this, we will evaluate if these neurons are communicating specifically with DMV neurons that innervate the liver and / or pancreas, and we will test the effects of ablation of the C1 neurons on the central action of insulin in Wistar and SHR rats. (AU)