Prenatal stress affects offspring behaviour through long-term epigenetic modifications.

PALLARES, ME.; FRASCH AC; MONTELEONE, M; ANTONELLI MC; PASTOR V; BROCCO, MA

Buenos Aires

Congreso; II Congreso de la Federación de Sociedades Latinoamericanas de Neurociencias (FALAN; 2016

FALAN

Maternal exposure to stress increases glucocorticoid levels which can affect offspring brain plasticity and development. Variability on stress response depends on the genetic and epigenetic background of each individual. In particular, dynamic epigenetic changes ?DNA methylation and histone modifications- are proposed to modulate plasticity in pathways regulating stress response, cognition and behavior. In this work we studied the effects of maternal stress on offspring hippocampal gene expression. Pregnant rat dams received restraint during the third week of gestation and male offspring were sacrificed on postnatal days 28 and 60. Prenatal stress treatment changed the expression of DNA methyltransferase dnmt3a, epigenetic transcription factor mef2a and the plasticity related genes bdnf and gpm6a mainly at PND60 indicating a persisting effect. No changes were found in methylcytosine dioxygenase 2 tet2 and histone deacetylase hdac2 expression levels. Since it has been proposed that perinatal experiences might carry useful information about the state of the external world, we performed behavioural testing of the offspring. We found that prenatally-stressed rats had reduced anxiety-like behaviour and also reduced depression-like behaviour. Altogether these results suggest that environmental-induced plasticity in the prenatal period can have long term consequences and affect offspring behaviour possibly through epigenetic adaptations.