Because of the trend for decrease in proliferation rates, and the robust decrease in neurogenesis observed 3 wk after exposure, we assessed whether a loss of forebrain stem cells might underlie the impairment of SVZ neurogenesis. To this end expression of SOX2-IR was determined. SOX2-IR within the SVZ also varied as a function of time (Fig. 5; main effect of time: F4,38=8.8, p<0.0001). SOX2-IR in the SVZ was not altered during 7 wk of daily alcohol vapour exposure, or after 3 d of abstinence following dependence. However, on day 7 of abstinence, SOX2-IR was reduced 25–35% (p<0.001) and remained reduced on day 21 (p<0.01). The long-lasting reduction in SOX2 is consistent with a loss of neural stem cells in the forebrain.
