The role of dorsomedial prefrontal cortex glucocorticoid receptors in engram allocation of recent contextual memory associated with neurocognitive networks

• Grant number: 23/07864-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Humanities - Psychology - Physiological Psychology
• Principal Investigator: Raquel Vecchio Fornari
• Grantee: Lorena Vido Lopes
• Host Institution: Centro de Matemática, Computação e Cognição (CMCC). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

Episodic or contextual memories are explicit long-term memories with specific information about space and time (context) of the event that generated their acquisition. These memories are modulated by the adrenal hormone Corticosterone (CORT). Studies suggest that type II glucocorticoid receptors, known as GRs, are present in high density in the hippocampus, amygdala and prefrontal cortex, areas related to the acquisition, consolidation and recall of contextual memory. Furthermore, recent studies suggest the participation of neocortical regions, specifically the Dorsomedial Prefrontal Cortex (dmPFC), in the modulation of regions from the Salience Network and Default Mode Network. DmPFC regions, such as the Pre-Limbic Cortex (PrL), have been suggested as modulators of short and long-term memory, with evidence in recent and remote contextual discrimination. The present project aims to identify and analyze the effects of blocking GRs in the dmCPF, immediately after the contextual fear conditioning (CFC) training, on the activation of regions from the Salience Network or Default Mode Network, associated with the formation of recent contextual memory. For this, it will be used brain sections from animals that received post-training infusions of the GR antagonist, mifepristone (RU-486), into the dmPFC, and tested after 2 days to verify both the strength and specificity of recent contextual memory. Immunohistochemical assays will be performed, with the purpose of identifying the FOS protein, indicative of neural activation, in the areas of interest. The results of this project may help to understand the neuroanatomical bases of recent emotional memory modulation.