The role of the hypothalamic pathway in the passive avoidance response to aversive sites

• Grant number: 23/07947-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: February 29, 2024
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: Karolina Domingues
• Grantee: Fernanda Ayumi Nagay Yoshihara
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Different aversive stimuli are processed by parallel circuits that ultimately promote the expression of appropriate defensive behaviors according to each situation. In rodents, these encephalic circuits may also present some superposition. Distinct situations like social defeat and passive avoidance mobilize areas in common, such as regions from the septo-hippocampal circuit and areas of the perifornical lateral hypothalamus, in particular, the juxtadorsomedial region (LHAjd). This region receives contextual information from the ventral subiculum (SUBv) and has connections to the premammillary nucleus and to the periaqueductal gray regions involved in the expression of defensive behaviors. Thus, we hypothesized that the LHAjd is involved in the detection of environmental boundaries imposed by aversive stimuli, regulating the expression of avoidance and risk assessment behaviors. To test this hypothesis, we will inhibit the SUBv using chemogenetic techniques. Our study is the first anatomical and functional investigation of an encephalic circuit involved in the detection and avoidance of threatening environments. A better understanding of this circuit in rodents may contribute in developing animal models relevant to the study of the neurobiology of anxiety.