Fig. 7

Experimental differentiation between focal and pan-nuclear neuronal γH2AX labeling. a Schematic of experimental design. Mice received an intraperitoneal injection of kainate (KA, 20 mg/kg) or saline (Sal) at 3–6 months of age. Fifteen minutes later, roughly half of them were exposed to 8 Gy ionizing radiation (IR). One hour later, all mice were sacrificed and their brains processed for fluorescence immunohistochemistry (b, c) and DI-PLA (d, e). b Representative confocal images of dentate gyrus sections co-labeled for γH2AX and NeuN. γH2AX single channel (left) and merged views (right) are shown. Scale bar: 200 μm. c Representative higher magnification views of sections similar to those in (b). Scale bar: 10 μm. d Representative confocal images from the apex of the dentate gyrus showing DI-PLA signals (left) and merged views with NeuN co-labeling (middle). High-magnification images (right) show individual neurons with DI-PLA signals (green) and NeuN immunostaining (red). Scale bar: 50 μm (left and middle), 10 μm (right). e Number of DI-PLA foci per 100 μm² neuronal area in the apex of the dentate gyrus. n = 4–7 mice per group. Two-way ANOVA revealed an effect of irradiation (p < 0.0001) but not of kainate (p = 0.8093) and no interaction between them (p = 0.5201). **p < 0.01, ***p < 0.001 vs. Sal by Holm-Sidak test. Bars represent means ± SEM