Epigenetics and the Environmental Regulation of the Brain's Genome and its Function

There are numerous examples of the enduring effects of early experience on neural function. In this paper we review the emerging evidence for epigenetics as a candidate mechanism for such effects. Epigenetics refers to a set of functionally relevant modifications to the genome that do not involve a change in nucleotide sequence. Such modifications include chemical marks that regulate the transcription of the genome. There is now evidence that environmental events can directly modify these marks, and thus gene transcription. Studies with rodent models suggest that environmental signals can act during both early development and in adult life to activate intracellular pathways that directly remodel the ‘epigenome’, leading to changes in gene expression and neural function. Parallel studies with clinically-relevant samples suggest comparable processes are related to psychiatric health. These studies define a biological basis for the interplay between environmental signals and the genome in the regulation of individual differences in behavior, cognition and physiology.