Our study (Zhou et al., 2011) with genomic sequencing directly examined mRNA-based transcriptome (RNA-Seq) in human postmortem hippocampal tissue from 24 men who were either cocaine addicts or alcoholics, or age-, ethnicity-, and postmortem interval-matched drug-free controls. Expression of 16,008 Refseq genes was detected. Among these, at an uncorrected P<0.05, we observed a total of 1994 differentially expressed genes in cocaine addicts, and 1275 differentially expressed genes in the alcoholics. After genome-wide multiple testing correction using a relatively stringent FDR cutoff of less than 0.2, there were 394 differentially expressed genes in the cocaine addicts and 48 in the alcoholics. At FDR<0.05, there were 80 differentially expressed genes in the cocaine addicts and 11 in the alcoholics (Fig. 10.1A and B).
