Dnmt3a2 in the Nucleus Accumbens Shell Mediates Cue-Induced Cocaine-Seeking Behavior

One of the main obstacles in treating drug addiction is the high rate of relapse even after prolonged periods of abstinence. Neuronal adaptions play a major role in drug craving and relapse. Many of these adaptions involve changes in gene expression, which in turn are mediated by epigenetic modifications. For example, DNA methylation is a fundamental epigenetic mechanism of gene expression regulation, and several studies have found DNA methylation patterns to change following drug exposure. Furthermore, pharmacological or genetic manipulation of the DNA methylation state can alter cocaine-seeking behavior. Cannella et al. sought to investigate the potential role of Dnmt3a2 in addictive behavior. In a set of cocaine self-administration experiments in rats, the authors found that Dnmt3a2 expression increased after cue-induced reinstatement of cocaine-seeking, but not after cocaine self-administration or extinction.