Amitriptyline treatment under chronic stress conditions: Effect on circulating stress hormones and anxiety in early maternally separated rats

COTELLA, EVELIN M.; MESTRES LASCANO, IVÁN; LEVIN, GLORIA M.; SUÁREZ, MARTA M.

Rodas

Workshop; Neurodevelopmental Programming and Phenotypic Plasticity: Implications for Stress, Aging and Health (Programme of European Neuroscience Schools,PENS); 2009

Federation of European Neuroscience Societies (FENS) International Brain Research Organization (IBRO)

development of behavioral and endocrine response to stress is influenced by early postnatal environment. Exposure to early stress can program the individual to display enhanced stress responsiveness along adult life. Adverse experiences during postnatal development may sensitize specific neurocircuits to subsequent stressors. In rats, long-term separation from the dam is considered to be one of the most potent natural stressors during development, inducing long-term alterations in HPA axis sensitivity and medullo-adrenal secretion. It is known that chronic treatment with tricyclic antidepressants can modulate the stress system through different actions at many levels of the central nervous system. The aim of this work was to determine the influence of early maternal separation on rats exposed to a variable chronic stress (VCS) protocol during adulthood, and see the effect of the tricyclic antidepressant amitriptyline on plasmatic concentration of the stress hormones (epinephrine, norepinephrine and corticosterone) and on anxiety-like behavior. Male Wistar rats were separated from the mother for 4.5 h every day for the first 3 weeks of life. Since postnatal day 50, animal were subjected to VCS during 24 days (5 types of stressors at different times of day). During the stress protocol rats were daily orally-administrated with amitriptyline (5 mg/Kg). After VCS rats were assessed for the anxiety-like behavior in the plus maze test and the next day they were decapitated to obtain plasma for hormones quantification by HPLC and RIA Chronic stress and maternal separation increased separately the epinephrine and norepinephrine secretion (p