Epigenetic mechanisms in brain development and in neurodegeneration.

Epigenetic mechanisms are important heritable modifications beyond genetic mechanisms. Interindividual epigenetic variants can lead to phenotypic variations even in identical genotypes. Studies on the epigenetic contributions to Alzheimer disease and other neurodegenerative diseases could provide more comprehensive and precise insights into the heritable and nonheritable mechanisms. This knowledge will enable the development of individually tailored preventive and therapeutic pharmacologic interventions. This chapter is divided into three sections. First, we provide a detailed introduction to four epigenetic mechanisms: DNA methylation, histone modifications, chromatin remodeling, and microRNAs. Next, we review published studies that explore the contributions of these epigenetic modifications to Alzheimer disease. Finally, we summarize the current understanding of each epigenetic modification and its influence on the development of the central nervous system.