Fig. 6

The elimination of microglia results in a reduced proliferation of astrocytes and disorganized astrocytic scar at the lesion border. a–d Confocal immunofluorescence microscopy of astrocytes (GFAP, purple) in spinal cord sections taken at the lesion epicenter in Cx3cr1^creER::R26-TdT::LysM-eGFP mice at 14 days post-injury (dpi). In mice fed with the control diet (a, c), astrocytes adjacent to the site of SCI exhibit elongated processes oriented parallel to the lesion border, thus forming a compact scar. This astrocytic response was compromised in mice depleted of microglia using PLX5622 (b, d), and associated with clusters of blood-derived myeloid cells (LysM-eGFP⁺, green cells in d) spreading outside of the lesion core. e Total counts of Sox9⁺ BrdU⁺ cells at the epicenter and both rostral (R) and caudal (C) to the lesion at 7 dpi in mice fed the control diet (blue), PLX73086 (red) or PLX5622 (green) (n = 4 mice per group). f–k Representative confocal images showing the proliferation of astrocytes (Sox9⁺, purple  cells), as demonstrated by their incorporation of BrdU (green cells), in mice treated with PLX5622 (f–h) or the control diet (i–k) and killed at 7 dpi. Data are expressed as mean ± SEM. *p < 0.05, **p < 0.01, PLX5622 versus the control group. Statistical analysis was performed using a two-way ANOVA followed by a Bonferroni’s post hoc test. Scale bars: (a and b, in b) 50 µm, (c and d, in d) 50 µm, (f–k, in k) 50 µm