CONICET | Buscador de Institutos y Recursos Humanos

ACUTE AND CHRONIC POSTNATAL STRESS ALTERS GLUTAMATE TRANSPORTER AND BEHAVIORAL RESPONSE. MM Odeón, AE Salatino, ML Orta, GB Acosta. ININFA- (CONICET-UBA). Junín 956. 5th floor, C1113AAD, Buenos Aires. E-mail: merodeon@hotmail.com The aim of this study was to evaluate the consequences of acute and chronic early life environmental manipulations on adult brain on glutamate transporter (GluT), evaluating the uptake of [3H]Glu by synaptosomes-enriched fractions isolated from cerebral frontal cortex (FC) and hippocampus (HIC) by kinetic parameters. Also we investigated the possiblility of relations between GluT and anxiety. In acute stress, control rats were moved to a separated cage while stressed rats were exposed to cold stress (4ºC) during 1 h. In repeated stress the rats were separated from their mothers and exposed to cold stress (4ºC) for 1 h at postnatal days during 20 days. These animals were allowed to a 30 days recovery period until adulthood. FC and HIC were dissected to study GluT and trunk blood samples were collected to determinate corticosterone levels. Acute stress in CF decreased the uptake while increased Km and Vmax in all ages studied. Repeated chronic stress did not change in uptake levels in both areas whereas kinetics parameters were modified. The levels of corticosterone increased on acute stress and unchanged on chronic stress. In chronic stress we found an increment in time spent in the illuminated site of the dark/light transition test. In summary, we have observed regional changes in GluT produced by stress. Chronic stress increased the time spent in the adverse environment. These results suggest that a exposure to postnatal stress at different periods after birth modifies GluT, affects hypothalamic-pituitary-adrenal (HPA) axis, which could be relevant to function of GluT in the adult rat brain and induces anxiolytic-like action in an animal model of anxiety.