Figure 3

METH does not affect differentiation of NPCs. A,B. NPCs maintained under proliferative conditions were exposed to METH (250 uM) for 24 hours, and fixed and immunostained 4 days later with antibody against Tuj1, GFAP, and RIP, and counterstained with DAPI. METH treatment does not result in premature differentiation (A), but does result in fewer total numbers of differentiated cells (B). C,D. NPCs in proliferating media were exposed to METH for 24 hrs, followed by culture for 4 days in differentiating conditions. METH does not alter the percentage of cells adopting neuronal, astrocytic, or oligodendrocyte markers. E, F. NPCs were cultured in differentiating conditions for 24 hours, followed by METH treatment for an additional 24 hours. Cells were analyzed 4 days after being placed in differentiating conditions. METH treatment after the onset of differentiation does not significantly affect fate choice (E) or numbers of differentiating cells (F). * p <0.01 ANOVA, compared to control.