Epigenetics and Brain Plasticity: Back to Function

Throughout our entire life, our brain is constantly shaped by the experience of both the outer and the inner environments. Sensory perceptions, as well as thoughts and feelings, are constantly processed and integrated in order to create a plastic representation of these environments and to efficiently adapt to perturbations; such a high demand of plasticity is met by the extraordinary capacity of our nervous system to quickly modify upon specific stimuli. Since a great number of neuronal plasticity processes rely on changes in gene induction/repression, a responsive, fine-tuned regulation of gene expression is of primary importance for a correct adaptation. Epigenetic regulation orchestrates the spatiotemporal regulation of gene expression in response to intracellular and extracellular stimuli, specifically through modifying chromatin accessibility to the transcriptional machinery, and is therefore likely to play a fundamental role in nervous system homeostasis and functioning. Despite being studied for more than forty years, our current understanding of the importance of epigenetics, particularly in highly complex fields such as neurophysiology and cognitive processes, is still very limited. This chapter aims to summarize our current knowledge on the role epigenetics plays in brain repair and how epigenome alterations may be involved in the pathophysiology of some common psychiatric disorders.