Equally important for providing precise, long-lasting changes in brain function associated with alcohol intake are histone modifications, which exert lasting control over transcriptional activity of target genes through modifications of the chromatin structure and function that make the DNA less or more accessible to transcription factors and enzymes. The basic unit of chromatin, the nucleosome, is a histone octamer wrapped by approximately 147 base pairs of DNA. Each core histone (H2A, H2B, H3, and H4) has a highly conserved amino (N)-terminal tail, which is subject through a range of posttranslational modification (PTM) marks at distinct residues/sites including acetylation and methylation of lysine residues and phosphorylation of serine residues (109). Histones acetylation and phosphorylation are associated with transcriptional activation, whereas histone methylation reflects both transcriptional activation and repression depending on the specific site and context of the modification. An important feature of histone PTMs is that they can influence each other in a synergistic or antagonistic manner, leading to a complex “histone code” (110). Of these histone PTMs, histone acetylation is the most widely investigated in terms of epigenetic mechanisms underlying
