Fig. 3

NMR cortical neurons show resistance to acid-induced cell death. Mouse (a) and NMR (b) cortical neurons were incubated for 2 h with either a pH 7.4 or pH 5 solution and then stained with Hoechst 33,342 to label nuclei and PI to label necrotic dead cells. c Percentages of PI-positive neurons (i.e. dead) at pH 7.4 were similar between mouse and NMR neurons. The percentage of mouse dead neurons was higher when cells were incubated in a pH 5 solution, compared to pH 7.4 condition and compared to the percentage of cell death obtained with NMR neurons at pH 5. NMR cortical neurons did not exhibit any significant difference with regard to cell death when exposed to pH 5.0 compared to pH 7.4. **** p < 0.0001, one-way ANOVA test, Tukey’s multiple comparison test. Percentages of each field of view were used to compare acidotoxicity between species. The number of fields of view analyzed for each condition are the following: n = 18 for mouse neurons (for both pH 7.4 and pH 5), n = 27 and 28 for NMR neurons at pH 7.4 and at pH 5, respectively; obtained from 3 independent cultures for both species