In the VTA, levels of α1 subunit immunoreactivity were significantly decreased after 12 weeks but not 1–4 weeks of treatment (Charlton et al. 1997). Papadeas et al. (2001) found that in the amygdala, α1 and α4 subunit expression was significantly decreased after two weeks of chronic EtOH consumption. In the nucleus accumbens (NAC), α4 subunit expression was decreased, but α1 subunit expression was not altered. In the VTA, there were no changes in α1 and α4 subunit expressions. Muscimol-stimulated Cl− uptake was enhanced in the extended amygdala, but not the NAC of EtOH-dependent rats. These results suggest that chronic EtOH exposure alters GABAA receptor expression in the amygdala and NAC and that decreased expression of α4 subunits is associated with increases in GABAA receptor function in the amygdala but not the NAC (Papadeas et al. 2001).
