Figure 8

MK801 treatment reduced Fas-ligand expression and TUNEL-like staining in the perilesional spinal cord tissue. No positive staining for Fas-ligand was found in the spinal cord tissue collected from Sham-operated mice (a). A substantial increase in Fas-ligand expression was found in inflammatory cells, in white matter and gray matter of the spinal cord tissues collected at 24 h after SCI (b). Spinal cord levels of Fas-ligand were significantly attenuated by MK801 treatment (2 mg/kg 30 min and 6 h after SCI induction) (c). Densitometry analysis of immunocytochemistry photographs (n = 5 photos from each sample collected from all mice in each experimental group) for Fas-ligand (d) was performed. In sham animals, no apoptotic cells were observed (e). At 24 h after the trauma, SCI mice demonstrated a marked appearance of dark brown apoptotic cells and intercellular apoptotic fragments (f). In contrast, tissues obtained from mice treated with MK801 (2 mg/kg 30 min and 6 h after SCI induction) demonstrated no apoptotic cells or fragments (g). The number of TUNEL positive cells/high-power field was counted in 5 to 10 fields for each coded slide (h). Figure is representative of at least 3 experiments performed on different experimental days. *p < 0.01 vs Sham; °p < 0.01 vs SCI. ND: not detectable