Photomicrographs of the morphological characterization of apoptotic neurons and astrocytes. A-D: photomicrographs of TUNEL and immunohistochemical double-stained sections 2 mm rostral from the epicenter in the ventral horn of injured spinal cords removed at 24 h post-SCI. A and B: TUNEL and NSE double-stained TUNEL-positive neurons at lower (A) and higher (B) magnifications. The arrowheads indicate TUNEL-positive nuclei in NSE-positive neurons. C and D: TUNEL and GFAP double-stained TUNEL-positive astrocyte at lower (C) and higher (D) magnifications. The arrows indicate TUNEL-positive nuclei in GFAP-positive astrocytes. E-J: photomicrographs of active caspase-3 and immuno-fluorescence double-stained sections 2.05 mm rostral from the epicenter in the ventral gray matter of injured spinal cords removed at 12 h post-SCI. E-G: p20 fragment and GFAP double-stained active caspase-3 with active astrocytes. E: active astrocytes (GFAP-positive, arrows); F: the same astrocytes stained for p20 (arrows). G: immuno-colocalization of E and F, showing caspase-3-positive astrocytes (arrows, yellow). H-J: p20 fragment and NSE double-stained neurons. H: NSE-positive neurons (arrowhead); I: the same neurons were also p20-positive (arrowhead). J: immuno-colocalization of H and I showing caspase-3-positive neurons (arrowhead, yellow). Scale bar = 100 μm.