MAP kinases pathway in the formation of neurospheres. AF-treated cells showed increased enlargement of neurospheres compared with control cells. In the presence of AF, application of the GSK-3 inhibitor, Li+, caused enlarged formation of neurospheres versus the control and AF alone. However, treatment with MEK inhibitors, such as PD98059 or U0126, inhibited the formation of neurosphere. *p < 0.05, versus CTL cells (CTL); #p < 0.05, versus vehicle (DMSO)-treated cells (DMSO), one way ANOVA, Tukey’s post hoc test. Scale bar indicates 100 μm.