Epigenetics, brain, behavior, and the environment

Some studies looked at whether DNA methylation (a process at the DNA level which affects which genes get turned on and turned off) has a link to increased risk for schizophrenia or schizophrenia-like conditions among the DES-exposed

Both men and women exposed to diethylstilbestrol (DES) in utero (hence having a body burden of the chemical) are more prone to depression compared to their unexposed siblings. Indeed, an issue of national concern is the significant environmental exposure to common-use chemicals in the household, a factor suggested as contributing to the increased incidence of affective disorders in the general population.

2010 Review Abstract

Early experiences can modify regulatory factors affecting gene expression in such a way that, although the DNA sequence itself is not changed, the individual’s physiology and behavior is substantially influenced.

In some instances these epigenetic effects are exerted upon exposure, while in other instances they are transmitted across generations via incorporation into the germline. Examples of both types of epigenetic effects are presented.

First, experience with siblings (littermates) organizes behaviors and their underlying neural substrates in such a way that, as adults, rats and knockout mice behave differently. Second, exposure to the fungicide vinclozolin early in pregnancy imprints the male lineage in such a manner that rats exhibit distinct behavioral profiles as well as unique patterns of gene expression in relevant brain regions.

Taken together, this work demonstrates that present and past environments alike modify both social and affiliative related behaviors and their related metabolic activity in specific brain nuclei as well as influencing the abundance of specific genes altering the epigenome in the target brain areas.



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