Fig. 7
Leukocytes migrate into the parenchyma. a A lesion core formed in the epicenter (yellow frame) via aggregation of YFP-positive cells in the gray matter. Sections of the spinal cord were harvested from LysM-YFP mice 4 h post-SCI (n = 3 independent experiments). WT: wild-type mice. Scale bar = 500 μm. b, c Whole-mount images of the spinal cords of LysM-YFP mice 6 h post-SCI. (b) Representative whole-mount images (displayed with a gamma correction of 1.5). Scale bar = 500 μm. (c) Quantification of the density of YFP-positive cells in the penumbra area. These cells were counted in 5003 μm.3 regions (white frame) 1 mm away from the lesion core in (b) (n = 3 to 4 mice). d Representative images of GR-1-positive leukocytes by immunostaining 6 h post-SCI. Scale bar = 25 μm. e Quantification of the GR-1-positive leukocyte density in multiple spinal segments 6 h post-SCI in (d) (n = 5 mice). f GR-1-labeled neutrophils (green) released nuclear citrullinated histone H3 (cit-H3, red) into nearby tissue 4 h post-SCI (n = 6 mice). Scale bar: left = 500 μm, right = 100 μm. g GR-1-labeled neutrophils (gray) released nuclear DNA/histone complex (red) and cytoplasmic neutrophil elastase (NE, green) into nearby tissue 4 h post-SCI (n = 7 mice). Scale bar = 25 μm. h Normalized area of the neutrophils released cit-H3, DNA/histone and NE in the neural parenchyma in (f, g). The area was normalized by the size of the pictures. Data are presented as the mean ± SEM; **P < 0.01, ****P < 0.0001; nested, one-way ANOVA (c, e, h)