Global microarray and proteomics studies have identified a number of gene groups and gene families that are differentially expressed in the prefrontal cortex of alcoholics. These gene groups include those involved in myelination, ubiquitination, apoptosis, cell adhesion, neurogenesis, and neural disease (Liu et al., 2006). The mechanism by which chronic alcohol abuse results in selective changes in gene expression in the prefrontal cortex is not known. Here we present the results of miRNA microarray analysis of the same samples used in our previous microarray studies. The aim of the study was to identify miRNAs which are differentially expressed in the prefrontal cortex. By profiling global miRNA expression changes and mRNA profiles in the same samples, we were able to determine the extent to which down-regulated genes may be targeted by miRNAs. In striking correspondence with the relatively small but abundant changes detected in mRNA expression, we now find that many miRNAs (approximately 35) change expression levels in the frontal cortex of the human alcoholics and that these changes are consistently small across the whole set of differentially expressed miRNAs. In
