Photomicrograph of RGCs without (A) or with CoCl
(B) or exposed to 1% O
(C). Arrow heads denote dead cells. TUNEL staining was performed as described in 'Methods' section to determine apoptotic RGC death following treatment. Insets: Photomicrograph of TUNEL-positive cells (green fluorescent) treated without (A) or with (B) or exposed to 1% O2 (C).