Importance of the medial amygdala nucleus efferent projections in the organization of social defense

• Grant number: 18/12763-2
• Support type: Scholarships in Brazil - Master
• Effective date (Start): August 01, 2018
• Effective date (End): September 30, 2020
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal researcher: Simone Cristina Motta
• Grantee: Erika Tissiana Sterde
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/18667-0 - Manipulating the neural circuit underlying social defense, AP.JP

Abstract

In rodents, the medial nucleus of the amygdala is known to be involved in the processing of olfactory information, main and accessory. Social information mobilizes a specific part, called posterodorsal (MeApd) that, to date, has GABA as the only identified neurotransmitter. However, the hypothalamic efferent projections of this nucleus, such as the ventral premammillary (PMV), the ventrolateral part of the ventromedial nucleus (VMHvl) and the medial preoptic nucleus (MPN), which are part of the social defense circuit, are activated after MeApd activation. We do not rule out the hypothesis that an intermediate structure, the main part of the Bed Nucleus of the Stria Terminalis (BNSTpr), is crucial for the functioning of this system. Thus, the objective of this project is to study the role of efferent MeApd projections during the expression of social defense behavior. For this, it is planned to transfect the MeApd of C57Bl/6 mice with the AAV-hSyn-eArch3.0-EYFP virus (inhibitory optogenetics) and position the optical fiber in one of the different MeApd targets, such as BNSTpr, VMHvl and PMV. Thus, it will be possible to observe the function of each of these projections in the organization of the behavior in question. Because it is a transitory inhibition, this experiment allows each animal to be exposed to the situation of intruder with and without inhibition of the specific projections.