ANRV398-PS61-19 ARI 14 September 2009 18:17 R E V I E W S I N A D V A N C E Epigenetics and the Environmental Regulation of the Genome and Its Function Tie-Yuan Zhang and Michael J. Meaney Sackler Program for Epigenetics and Psychobiology of McGill University, Douglas Mental Health University Institute and the Singapore Institute for Clinical Sciences, Montreal, Quebec, H4H 1R3 Canada; email: michael.meaney@mcgill.ca Annu. Rev. Psychol. 2010. 61:19.1–19.28 The Annual Review of Psychology is online at psych.annualreviews.org This article’s doi: 10.1146/annurev.psych.60.110707.163625 Copyright c  2010 by Annual Reviews. All rights reserved 0066-4308/10/0110-0001$20.00 Key Words maternal care, stress responses, DNA methylation, gene x environment interactions, glucocorticoid receptor Abstract There are numerous examples in psychology and other disciplines of the enduring effects of early experience on neural function. In this ar- ticle, we review the emerging evidence for epigenetics as a candidate mechanism for these effects. Epigenetics refers to 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 environmen- tal events can directly modify the epigenetic state of the genome. Thus studies with rodent models suggest that during both early develop- ment and in adult life, environmental signals can activate intracellular pathways that directly remodel the “epigenome,” leading to changes in gene expression and neural function. 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. 19.1