The effects of repeated early maternal separation and cold stress on brain development

ADRIAN E SALATINO; MARIA MERCEDES ODEON; MARIA LUZ ORTA; GABRIELA ACOSTA

Huerta Grande, Córdoba. September 4-6, 2009

Congreso; First Joint Meeting of the Argentine Society for Neuroscience (SAN) and the Argentine Workshop in Neuroscience (TAN); 2009

SAN y Taller de Neurociencias

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. The aim of this study was to investigate the consequences of repeated early maternal separation and cold stress exposition on GABAergic function and determinate whether the combination between cold and desensitization to maternal separation was an age-specific event on adult brain. Rats pups were separated from their mother and exposed to cold stress (4°C) for 1 h at postnatal day (PD) 5, 7 and 13 during 20 days. These animals were allowed to a 30 days recovery period until adulthood. The rats were killed by decapitation and trunk blood samples were collected to measure corticosterone levels. Frontal cortex (FC) and hippocampus (HIC) were dissected in order to study GABA uptake. Our results shows that the time course of repeated stress decreased GABA uptake only on FC at PD5, while at PD7 diminished significantly either on FC or HIC. Also, at PD13, we found a significant GABA uptake decrease on HIC. Chronic stress did not alter the basal levels of corticosterone at the different ages studied. These preliminary results support the notion that the development of the FC is affected by stressors during early life. The findings are in agreement with the hypothesis of compensatory changes development in response to repeated stress. Although we need to carry out more tests, we propose FC as key in the development of adaptative mechanisms. Supported by UBACYT B019 and CONICET, PIP 5869