Assesment of the Impact of Acute and Chronic Psychosocial Stress on Plasma Corticosterone Levels in Female and Male Mice

• Grant number: 24/07540-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Ricardo Luiz Nunes de Souza
• Grantee: Katellyn Costa Silva
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Stress is a recognized risk factor for the development of neuropsychiatric diseases. The effects produced by stress can be experimentally investigated through the animal model of social defeat witness, especially in behaviors associated with anxiety and depression. However, the behavioral and hormonal effects underlying stress, such as sex, type of stressor, frequency, and exposure to new stressors, are not yet fully understood. In this sense, this study aims to understand how the frequency of exposure to direct and indirect psychosocial stress affects corticosterone levels in mice, paying attention to differences between sexes and response to new stressors. For this purpose, male and female Swiss Webster mice will be used. The animals will be independently exposed to psychosocial stress protocols, either directly or through exposure and observation of social defeat sessions, in acute, chronic, and combined forms with a new stressor for periods of one and ten days. After the social defeat protocols, the animals will be euthanized and subjected to a cardiac puncture for blood plasma collection. The Enzyme-Linked Immunosorbent Assay (ELISA) technique will be employed for the analysis of plasma corticosterone levels in the different experimental groups. The proposed analyses may clarify the influences of sex, frequency of psychosocial stressors, and reaction to new stressors on the function of the hypothalamic-pituitary-adrenal (HPA) axis in male and female mice.