Epigenetics in learning and memory

While the cellular and molecular mechanisms of learning and memory have long been a central focus of neuroscience, it is only in recent years that attention has turned to the epigenetic mechanisms behind the dynamic changes in gene transcription responsible for memory formation and maintenance. Epigenetic gene regulation often involves the physical marking (chemical modification) of DNA or associated proteins to cause or allow long-lasting changes in gene activity. Epigenetic mechanisms such as DNA methylation and histone modifications (methylation, acetylation, and deacetylation) have been shown to play an important role in learning and memory. While the cellular and molecular mechanisms of learning and memory have long been a central focus of neuroscience, it is only in recent years that attention has turned to the epigenetic mechanisms behind the dynamic changes in gene transcription responsible for memory formation and maintenance. Epigenetic gene regulation often involves the physical marking (chemical modification) of DNA or associated proteins to cause or allow long-lasting changes in gene activity. Epigenetic mechanisms such as DNA methylation and histone modifications (methylation, acetylation, and deacetylation) have been shown to play an important role in learning and memory. DNA methylation involves the addition of a methyl group to a 5' cytosine residue. This usually occurs at cytosines that form part of a cytosine-guanine dinucleotide (CpG sites). Methylation can lead to activation or repression of gene transcription and is mediated through the activity of DNA methyltransferases (DNMTs). DNMT3A and DNMT3B regulate de novo methylation of CpG sites, while DNMT1 maintains established methylation patterns. S-adenosyl methionine acts as the methyl donor.