BDNF expression is induced by subtoxic levels of oxidative stress in PC12 cells. (A) Differentiated PC12 cells were stimulated with the indicated concentrations of H2O2 for 15 h. Cell toxicity was measured by LDH assay. Data shown represent mean ± SEM, tested using a one-way ANOVA with Tukey’s post-test (**p <0.01, n =9). (B) Differentiated PC12 cells were stimulated with the indicated concentration of H2O2 for 30 min. Total and phosphorylated proteins were evaluated by western blotting analysis. Three independent experiments were performed and representative data are shown.