Fig. 7
H2O2-treated neurons display decreased ARNT2 which precedes increases in cleaved-caspase 3 staining/apoptotic cell death. DIV7 neurons were treated with 25 or 50 μM H2O2 for 1 and 3 h and stained to examine ARNT2 and cleaved caspase-3 intensity. Data points represent cells pooled from 11 random regions from wells treated in duplicate. *p ≤ 0.05 ANOVA followed by Bonferroni’s multiple comparisons test to PBS-treated cells for the same treatment time; bars represent the average mean intensity and whiskers the SEM; 1 of 2 representative experiments with similar results is shown. c Representative images from a to b are shown. PBS-treated wells show numerous MAP2+ cells staining brightly or moderately for ARNT2 (asterisk); staining for cleaved caspase-3 is negligible. In contrast, exposure to 25uM H2O2 significantly reduced ARNT2, without associated increases in cleaved caspase-3 that are not detected until exposure to 50 μM H2O2 for 3 h. Fifty micromolars of H2O2 also increased the number of condensed nuclei and reductions in MAP2+ dendrites (arrow)