Infantile stress and neuropeptide Y (NPY) role in vulnerability of adolescent rats to development of PTSD

• Grant number: 17/50378-0
• Support type: Regular Research Grants
• Duration: May 01, 2018 - April 30, 2020
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal researcher: Deborah Suchecki
• Grantee: Deborah Suchecki
• Principal researcher abroad: Gal Richter-Levin
• Institution abroad: University of Haifa, Israel
• Home Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 15/26364-4 - Neurobiologic mechanisms involved in the long-term emotional effects of maternal deprivation, AP.R

Abstract

Maternal care inhibits the activity of the hypothalamic-pituitary-adrenal (HPA) axis. Separation of neonatal rats from their mothers for 24h increases basal, stress-and ACTH-induced corticosterona (CORT) plasma levels. Being a catabolic hormone, elevated CORT may alter the developmental trajectory of brain structures involved in emotional behaviors. Maternal deprivation imposed on postnatal day (PND) 3 (DEP3) or on day 11 (DEP11), produce distinctive consequences in emotional behavior of male and female adolescent rats. Whereas DEP3 adolescents of both sexes show increased anxiety- and depressive-like behaviors in the elevated plus maze, novelty suppressed feeding, sucrose preference and forced swimming test, DEP11 male and female adolescent rats displayed more depressive-like behavior than control, non-deprived, but less than DEP3 counterparts. Evaluation of NPY, a resilience factor, indicates that both groups produces less of this neuromodulator. Therefore, the goal of this proposal is to test whether this paradigm, applied on PNDs 3 or 11, increases the vulnerability of adolescent rats to develop posttraumatic stress disorder (PTSD) induced by the underwater trauma (UWf), and to carry out a behavioral profiling in order to examine the prevalence of extreme profile in animals with a history of infantile stress. Our hypothesis is that, regardless of the age of maternal deprivation, these male and female adolescents will be more affected in the behavioral profiling of PTSD. (AU)