Finally, a comparison of transcriptional and epigenetic changes induced by chronic cocaine or ethanol abuse in humans was conducted in postmortem hippocampus using whole transcriptome sequencing [42]. A total of 394 and 48 genes were differentially expressed in cocaine addicts and alcoholics, respectively, compared to drug-free subjects. There were 29 genes in common, including several transcriptional regulators and a number of small nucleolar RNAs, which guide chemical modification of pre-RNA molecules. Mitochondrial inner membrane function, however, was uniquely disrupted in the hippocampus of cocaine addicts.
