FIGURE 6.

PP2A-Pep inhibits progressing excitotoxic neuronal death. Neurons were stressed for 60 min with 50 μM glutamate and treated with no peptide (control), PP2A-Pep (10 μg/ml) or Ctrl-Pep (10 μg/ml) 0, 3, 6, 12, 24, and 48 h after the glutamate stress. After additional 24 h of incubation, the cultures were stained with DAPI for total cells (glia plus neurons) and with an antibody directed against NeuN for neurons. (A) Schematic representation of the experimental design. (B) Representative images (scale bar: 100 μm) are shown for the untreated control and for the condition where the peptides were immediately administered after the glutamate stress (0 h), or after 6 and 48 h. (C) Quantification of neuronal loss. Number of neurons were normalized to the untreated control cultures. The data represent the mean ± SD of 35–112 frames (fields of view) per experimental condition from three independent experiments. Brown–Forsythe and Welch ANOVA with Games Howell’s multiple comparison test (ns, p > 0.05, *p < 0.05, ***p < 0.0005, ****p < 0.0001).