Postnatal acute stress-induced changes in neuronal cerebral cortex of L-serine and GABA uptake.

SCOLARI MJ, CHELUJA MG AND ACOSTA GB.

Mar del Plata, 9-11 de Noviembre

Congreso; XXXVII Reunión Científica Anual de la Asociación Argentina de Farmacología Experimental (SAFE).; 2005

SAFE

During early development, a number of reports demonstrated that the postnatal stress modified the neuronal responses to aminoacidergic transmitters, this fact, appears to be associated with neurobiological alterations. In this work, we investigated the influence of synaptic activity on L-Serine (Ser) and GABA  uptake responses in postnatal acute cold stress conditions. Experiments were performed with cerebral cortex (CC) of rats in different postnatal day of the birth until young adulthood.   Neonates were stressed by cold stress for 1 hour at 4ºC. Unhandled neonates, left undisturbed in their home cages, served as control. Upon termination of cold stress exposure, neonates were killed by decapitation. The brain was removed from the cranial cavity; CC was dissected. Neonatal CC synaptosomes were freshly prepared for determination of incorporation of radiolabeled amino acids in Krebs Ringer buffer at 30°C. We observed that the acute cold stress increased the time course both Ser and GABA uptake at 7, 13, 21 postnatal days while decreased at 5 postnatal day and in adult stage compared with control group. The values of Vmax and Km either L-serine or GABA uptake decreased in the stressed animals respective with control groups. These results suggested a possible relation between acute cold stress and the mechanism associated with neuronal activities of both Ser and GABA during postnatal development.