From Figure 1A and Table 2 it can be seen that in cocaine addicts there was down-regulation of GAD1 (p = 0.013) and GAD2 (p = 0.013). These genes encode enzymes that synthesize GABA from glutamate. Both cocaine addicts and alcoholics had lower expression of GABBR1 (p = 0.013) (Figures 1A, S2) and a trend (p = 0.050) towards lower expression of SLC6A1 that encodes the GAT1 transporter that is responsible for re-uptake of GABA from the synaptic cleft.
