The Role of Sex in Vagus Nerve Stimulation-Induced Modulation of Contextual Fear

• Grant number: 25/06416-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 31, 2025
• End date: August 30, 2026
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Amanda Ribeiro de Oliveira
• Grantee: Leticia Mitsuko Taguchi
• Supervisor: Christa Mcintyre Rodriguez
• Host Institution: Centro de Educação e Ciências Humanas (CECH). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: University of Texas at Dallas (UT Dallas), United States
• Associated to the scholarship: 23/02122-8 - Involvement of mineralocorticoid and glucocorticoid receptors in the ventral tegmental area in the expression of conditioned and unconditioned fear in male and female rats, BP.DR

Abstract

Fear and anxiety are critical emotional responses essential for survival,but their dysregulation can lead to mental disorders, affecting a significant portion of thepopulation, particularly women. Exposure-based therapies, commonly used to treat fearrelated disorders such as Post-Traumatic Stress Disorder (PTSD) and ObsessiveCompulsive Disorder (OCD), often show limited efficacy due to difficulties in recallingextinction memories. Vagus Nerve Stimulation (VNS) has shown promise as an adjuncttreatment by enhancing memory consolidation and alleviating anxiety symptoms.However, despite the higher prevalence of fear-related disorders in women, VNS effectsin females remain poorly understood. Most rodent studies on VNS and fear conditioninghave focused on cued fear extinction and used only male subjects. This study aims toinvestigate the effects of VNS on contextual conditioned fear in male and female rats.Sprague-Dawley rats will undergo training in a contextual fear conditioning task (Day 1)followed by one (Day 2) or three days (Day 2, 3 and 4) of extinction sessions. VNS willbe administered on Day 1 or Day 3. After the experiment, brains will be collected for cFos immunohistochemical analysis in key regions involved in fear and memoryprocessing, including the hippocampus, amygdala, prefrontal cortex, and ventraltegmental area. VNS is expected to enhance contextual conditioned memory in bothsexes. Understanding VNS effects on contextual fear conditioning in male and femalerats will provide valuable insights into its therapeutic potential for fear-related disorders,helping to bridge the gap in sex-inclusive research.