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.