Consequences of acute or chronic early maternal separation in adulthood: changes on neural

GB ACOSTA; AE SALATINO; MM ODEON

Florencia, Italia. 14-18 de Julio

Congreso; 8th IBRO World Congress of Neuroscience and the Italian Society for Neuroscience and of the Organizing Committee; 2011

The Italian Society of Neuroscience SINS - International Brain Research Organization IBRO

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. We studied the effect of acute and chronic maternal separation (MS) at different stages of postnatal life on the glutamate uptake evaluating the uptake of glutamate (Glu) by fresh synaptosomes isolated from frontal cortex (FC) and hippocampus (Hic), determination of corticosterone levels, and the expression of GLT-1 and EAAT3 by western blot. We worked with two different protocols by acute or chronic MS. We sacrificed the animals by decapitation. FC and Hic were dissected on a Petri dish at 0ºC and trunk blood samples were collected to determinate corticosterone levels. The time course of Glu uptake, we demonstrated that the end results of variations in the number of transporters and affinity for their substrates. It is probable that the variation observed in the kinetic parameters are produced by MS+stress and its biological mediators or by a compensatory effect of the organism. The levels of corticosterone decreased in almost ages studies in acute MS while increased at chronic MS. Using immunoblotting we showed that detectable levels of the transporters subtypes: EAAT3 (EAAC1) is neuronal and GLT-1 (EAAT2) is primarily astrocytic. GLT- 1 expression progressively increasing to adults levels; while the expression of EEAC3 was greater in newborn compared with adult brain. These results suggest that an exposure to postnatal stress at different periods after birth modifies GluT, affects hypothalamic-pituitaryadrenal (HPA) axis, which could be relevant to function of GluT in the adult rat brain altering the glutamatergic system.