Gene expression analysis in a rat model of maternal depression and in utero SSRI exposure

The purpose of this study is to evaluate the effects of maternal depression and its treatment on the offspring's gene expression in adulthood. Female rats were implanted with osmotic minipumps that delivered clinically relevant concentrations of the SSRI escitalopram throughout pregnancy. After mating, females were exposed to chronic mild stress. The offspring were analyzed at adulthood to determine the long‐term effects of prenatal stress and/or escitalopram exposure. Evaluation at baseline showed statistically significant changes in several endocrine measurements but these were not believed to be physiologically relevant. Microarray analysis of the hippocampus and hypothalamus comparing all treatment groups revealed no significantly regulated genes. RT‐PCR was used to determine more subtle gene expression differences in the hippocampus (i.e., <1.5‐fold changes). The mineralocorticoid receptor, which contributes to regulating the stress response, displayed a blunted increase in expression after the combination of prenatal stress and chronic adult stress (p < 0.05) compared to controls. The endpoints examined indicate that escitalopram use during pregnancy produced no alterations in the offspring.