Fig. 5.

Aging and Aβ expression increase the sensitivity of Drosophila to oxidative stress. Young (day 2) control flies, and those expressing Aβ40, were relatively resistant to 72 hours of hydrogen peroxide treatment. All older flies (day 20) were more sensitive to this oxidative challenge. Remarkably, young flies expressing the aggregation-prone Aβ42 isoforms were as sensitive to oxidative stress as the old flies. No deaths were observed in the control experiment where the flies were kept on equivalent food without hydrogen peroxide (data not shown). The statistical significance of mortality differences between genotypes with age was assessed by 2-way ANOVA (* p < 0.05, ** p < 0.01, *** p < 0.001, error bars show the standard deviation). Abbreviations: ANOVA, analysis of variance; Aβ, amyloid beta; ns, not significant.