Responsiveness of CRFPVN and Lepr+ neurons to fasting in mice with obesity induced by high-fat diet

• Grant number: 22/13459-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2023
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Rodrigo César Rorato
• Grantee: Ana Beatriz de Assis Marçal
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

The increase in the CRFPVN neurons activity followed by the activation of the Hypothalamus-Pituitary-Adrenal axis it's a mechanism observed in response to the stress of food deprivation. At least in part, the increased activity of the HPA axis during fasting is associated with decreased plasma concentrations of leptin. Interestingly, there are studies showing that animals with high-fat diet-induced obesity shows significant increase in plasma corticosterone concentrations and are hyperleptinemic, but leptin resistant. The leptin receptors are expressed in several regions of the CNS, but not in CRFPVN neurons, indicating that leptin's effects on the activity of the HPA axis are indirect and mediated by the modulation of another group of neurons sensitive to leptin and that can be directly connected with CRFPVN neurons. Therefore, in this study we aim to evaluate the activity of CRFPVN neurons in animals with diet-induced obesity and fasted. In addition, using the same experimental model of metabolic stress we intend to analyze the activity of hypothalamic and extra-hypothalamic neuronal groups, expressed in regions that is already known to directly project to CRFPVN neurons.