Effects of postnatal stress on the activity of aminoacidergic transporters on the brain.

ACOSTA, GABRIELA BEATRIZ

Rosario, 24-26 de Noviembre de 2009

Congreso; XLI Reunión Científica Anual de la Asociación Argentina de Farmacología Experimental (SAFE).; 2009

Asociación Argentina de Farmacología Experimental

EFFECTS OF POSTNATAL STRESS ON THE ACTIVITY OF AMINOACIDERGIC TRANSPORTERS ON THE BRAIN Gabriela Beatriz Acosta Instituto de Investigaciones Farmacológicas (ININFA) CONICET-UBA. Junín 956. 5º floor, C1113AAD, Buenos Aires. E-mail: gacosta@ffyb.uba.ar During postnatal development, the central nervous system (CNS) is highly sensitive to the effects of drugs, stressors and environment. Early life events have profound consequences in growth and development. It is well known that animals exposed to stressful stimuli during their early life develop different neurological disorders when they become adults. The aim of this study was to evaluated the consequences of repeated early maternal separation and exposed to cold stress on adult brain on GABAergic function and determinate whether the combination between desensitization to maternal separation and cold was an age-specific. Rats´ pups were separated from their mother plus cold exposure (4°C) for 1 h at postnatal day (PD) 5, 7, 13 and 21 during 20 days. These animals were allowed a 30 days recovery period until adulthood. The rats were killed by decapitation and collecting trunk blood. Frontal cortex (FC) and hippocampus (Hic) were dissected. We studied GABA uptake, corticosterone levels and GAT-1 expression by western blot. Repeated stress decreased GABA uptake only on FC at PD5, while at PD7 diminished significantly either FC or Hic after stress. Chronic stress decreased the levels of corticosterone at the different ages studied. While GAT-1expression increased on FC. We would support the idea that early life environmental manipulations have an influence on hypothalamic-pituitary- adrenal (HPA) axis and alter the expression of plasticity related neuronal protein. Furthermore early stress in the life affects the FC of adult rat brain. The findings are in agreement with hypothesis of compensatory changes develop in response to repeated stress and we suggest that these time-dependent alterations might reflect adaptative processes and FC as a key in the development. These results suggest that a repeated early maternal separation in different periods after birth modified GABA uptake, levels of corticosterone and the expression of GAT-1 , which could be relevant to function of transporter in the adult rat brain. Supported by UBACYT B019