Bridging Environment and DNA: Activity-Induced Epigenetic Modification in the Adult Brain

Abstract

The brain continuously receives sensory information from the outside world and processes the information into electrical activity. Sensory experience in the form of neuronal activity leaves marks in neurons by dynamically modifying neuronal properties, such as connectivity, excitability, gene expression and epigenetic modification. Although DNA methylation has long been considered to be a relatively stable epigenetic marker, recent studies demonstrate that epigenetic modification through changes in DNA methylation can be induced by neuronal activity, learning-related stimuli, and various external cues. Activity-dependent induction of the gene Gadd45b links neuronal activity to DNA demethylation machineries that act in specific loci of the neuronal genome. Thus, a novel mechanism has emerged to bridge the environment and DNA through epigenetic modification of the neuronal DNA methylation landscape, which may have widespread implications for novel mechanisms of neural plasticity and potential therapeutic interventions for neurological and psychiatric disorders.