Assessment of Epigenetic Changes Associated with Care Giving in the Medial Prefrontal Cortex of Adolescent Rats
Date
2013-05
Authors
Journal Title
Journal ISSN
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Publisher
University of Delaware
Abstract
An early stressful environment, such as child abuse, has been shown to have
profound effects on neurodevelopment and later behavior. The field of epigenetics has
provided insight into how long-term changes in gene expression and behavior can be
catalyzed by early-life stressful experience and maintained throughout one’s lifetime
by way of chromatin modifications. In the current study, we aimed to characterize
epigenetic changes to Bdnf and Reelin, genes important in development and plasticity,
in the adolescent medial prefrontal cortex (mPFC) after manipulation of infantcaregiver
experiences. Using a within-litter design, rat pups were exposed to either an
abusive or nurturing caregiver (maltreatment or cross-foster care conditions,
respectively) for 30 minutes per day during the first postnatal week. Biochemistry
results indicate a significant decrease in methylated DNA associated with Bdnf exon
IV for maltreated females and an increase in methylated DNA associated with Bdnf
exon I for maltreated males. Gene expression assays detected a decrease in the
expression of Reelin and Bdnf in males who experienced nurturing care outside of the
home cage (cross-foster care). The data demonstrate differential epigenetic effects of
early life stress in the mPFC that are present past the initial period of manipulation and
are specific to caregiving environment, sex, and gene locus.