Figure 1

HZE exposure-induced suppression of adult neurogenesis in the dentate gyrus of the hippocampus is transient. Representative images (magnification 10 ×) of immunoreactivity of DCX + cells in coronal brain sections from male (a) and female (b) mice two months and 12 months post HZE exposure. Quantification of DCX + cell density in sections 2 months post exposure reveals deficits in both (c) male mice, One-way ANOVA, F(3,16) = 13.20, P = 0.0001, Tukey’s post hoc test: 0 cGy vs. 10 cGy, P = 0.070; 0 cGy vs. 50 cGy, P < 0.0001; 0 cGy vs. 100 cGy, P = 0.003, 10 cGy vs. 50 cGy, P = 0.019, 10 cGy vs. 100 cGy, P = 0.427, 50 cGy vs. 100 cGy, P = 0.312] and (e) female mice, One-way ANOVA, F(3,16) = 15.08, P = 0.0001, Tukey’s post hoc test: 0 cGy vs. 10 cGy, P = 0.009; 0 cGy vs. 50 cGy, P = 0.002; 0 cGy vs. 100 cGy, P < 0.0001, 10 cGy vs. 50 cGy, P = 0.862, 10 cGy vs. 100 cGy, P = 0.047, 50 cGy vs. 100 cGy, P = 0.190, but elevated density of DCX + cells 12 months post radiation exposure in both (d) male mice, One-way ANOVA, F(3,14) = 4.85, P = 0.01, Tukey’s post hoc test: 0 cGy vs. 10 cGy, P = 0.025; 0 cGy vs. 50 cGy, P = 0.047; 0 cGy vs. 100 cGy, P = 0.046, 10 cGy vs. 50 cGy, P = 0.988, 10 cGy vs. 100 cGy, P = 0.947, 50 cGy vs. 100 cGy, P = 0.996, and (f) female mice One-way ANOVA, F(3,12) = 9.92, P = 0.001, Tukey’s post hoc test: 0 cGy vs. 10 cGy, P = 0.002; 0 cGy vs. 50 cGy, P = 0.018; 0 cGy vs. 100 cGy, P = 0.005, 10 cGy vs. 50 cGy, P = 0.123, 10 cGy vs. 100 cGy, P = 0.798, 50 cGy vs. 100 cGy, P = 0.362, compared to age-matched sham-irradiated controls (0 cGy) is shown in bar graphs. *P < 0.05 compared to 0 cGy. Data represents mean ± SEM. n = 5 mice per dose per time point, 6 sections per mouse.