REVERSIBLE DNA-ALTERATION IN THE STRESS RESPONSE
Stress response is mediated by hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid feedback on CRF has an important role in its regulation. Maternal behaviour during development can have a relevant influence on stress responses of the offspring later in life as a result of lasting epigenetic changes in the methylation state of the hippocampal glucorticoid receptor promoter. In particular, high levels of maternal care are associated with hypomethylation and low levels with hypermethylation of this promoter.
Weaver and colleagues demonstrated that enzymatic mechanisms that underlie DNA methylation and demethylation can be activated also in adult post-mitotic hippocampal rat neurons (Reversal of maternal programming of stress responses in adult offspring through methyl supplementation: altering epigenetic marking later in life. Journal of Neuroscience 25, 11045-11054, 2005).
The authors speculate that epigenetic modifications during development and adulthood could be influenced by dietary modification of methylation and might offer a potential therapeutic solution for the treatment of stress disorders and a range of other nervous system conditions, such as fragile-X syndrome and schizophrenia.