Social defensive behaviors: Medial Amygdala and the onset of psychopathologies.

• Grant number: 24/09749-9
• Support Opportunities: Scholarships abroad - Research
• Start date: December 15, 2024
• End date: December 14, 2025
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: Simone Cristina Motta
• Grantee: Simone Cristina Motta
• Host Investigator: Ruediger Klein
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Max Planck Institute For Biological Intelligence, Germany

Abstract

Social defense is expressed when the source of threat is a conspecific. But every time someone faces such a threat, it changes the way this animal perceives and reacts to conspecifics. In mice, several re-exposures to social defeat are commonly used as animal model for depression, leading, for instance, to social aversion and less interest in palatable food (anhedonia). Our laboratory studies the neural circuit activated during the expression of social defensive behavior. In this context, we found that the re-exposure to conspecific threats, usually used in the literature to generate depressive-like states in rodents, reduced the medial amygdala (MeA) activation, that vehiculates both accessory and main olfactory cues to the social defensive behavior circuit. This decrease in MeA activation was accompanied by changes in behavioral expression, like increase in freezing and passive forms of defensive behaviors. How a decrease in activation of neural pathways that are conveying social information leads to the behavioral expression that generates depressive-like states remains unknown, but exploring and understanding these circuits could be an important step to understand neural mechanisms that lead to depression and other psychopathologies.