Figure 1.

Bax is required for IR-induced apoptosis in the cerebellum and dentate gyrus. (A) Apoptosis is almost absent in the P5 Bax−/− dentate gyrus (c and d) compared with WT tissue (a and b) 18 hr after IR. Apoptosis was assessed by neutral red (a and c) and Sytox green (b and d). (B) Apoptosis occurs in the EGL of the P5 WT cerebellum (a and e) but is markedly reduced or absent in Atm−/− (b and f), p53−/− (c and g), and Bax−/− (d and h) tissue after IR. In contrast to in the cerebellum, apoptosis in the central region of the WT (i) and Bax −/− retina (k) are indistinguishable, whereas in the Atm−/− retina (j), it is absent. a–d are neutral red stained, and e–k are in situ end labeling-stained tissue 18 hr after IR. (×200.)