Prenatal stress increases plasma corticosterone and hippocampal Nitric Oxide Synthase expression in rat´s offspring.

MAUR DG; BURDET B; GENARO A.M; ZORRILLA ZUBILETE M.A.

Huerta Grande

Congreso; II Reunion Conjunta de Neurociencias; 2010

Sociedad Argentina de Investigación en Neurociencias y Taller Argentino de Neurociencias

Stress during early stages of development induces long lasting neurochemical and neuroendocrine alterations that in turn develop into behavioural deficits. We have already established that prenatal stress (PS) induces a deficit in spatial and associative memory and alterations in anxiety-like behaviour, together with a reduction of nitric oxide synthase (NOS) activity in adulthood. The aim of the present study was to determine if PS has an effect on plasma corticosterone levels and in hippocampal NOS expression. Methods: Pregnant Wistar rats were restrained three times a day, 45 minutes each, during the last week of pregnancy. Offspring was sacrificed at postnatal day 7 (PN 7) and analyzed for hippocampal NOS mRNA by RT-PCR and for plasma corticosterone levels by ELISA. Results: nNOS mRNA levels were increased by PS. We also found an increased level of plasma corticosterone. Discussion: It has already been shown that different models of PS induce alterations in the HPA axis that in turn develop into behavioural alterations. We have found behavioural abnormalities in PS rats, together with alterations in nitric oxide synthase expression and activity, both in cerebellum and hippocampus. In this study we show that this modifications appear as early as PN 7. Indeed, plasma corticosterone and hippocampal nNOS mRNA levels were increased in PS rats. We are currently evaluating a possible correlation between these parameters, in order to establish its relationship with the behavioural abnormalities observed.