Figure 4. Irradiation induced a more pronounced and protracted microglia increase in the juvenile hippocampus.

The numbers of microglia were quantified in the GCL (including the SGZ) and the entire DG in sham controls (SH) or 6 h, 24 h, 7 days and 30 days after irradiation (IR). Data are shown as mean ± S.D., n = 6 for the sham groups, n = 10-11 for the irradiated groups. Asterisks indicate comparison between irradiated groups and the corresponding sham controls. For the juvenile brains, each time point is compared with a separate control group, taking into account possible developmental changes. ^***P < 0.001.