Fig 2. Proliferation and demyelination in the early stages after crush injury.

(a) IF images of sciatic nerve cross sections from WT and Prnp^ZH3/ZH3 mice at 5 d.p.c. revealed many ki67-positive proliferating cells. The contralateral uninjured nerve from a WT mouse showed no proliferating cells. Channels for ki67 and DAPI are shown separately. Scale bar: 50 μM. (b) Ki67-proliferation index (% ki67-positive nuclei) as quantified from IF images was highest at 5 d.p.c. and decreased at later stages post crush injury. No significant differences were detected between WT and Prnp^ZH3/ZH3 mice at 5, 16 and 30 d.p.c. (two-way ANOVA, Sidak’s multiple comparisons test, p > 0.05). n.s. = not significant. (c) IF images from crushed sciatic nerves at 5 d.p.c. stained for ki67, S100, CD68 and DAPI. The majority of ki67-positive nuclei colocalize with S100-positive Schwann cells (white arrows), whereas only few CD68-positive macrophages have ki67-positive nuclei (white triangles). Scale bar 25 μM. (d) Quantification of intact appearing myelin profiles at 5 d.p.c. from EM images revealed no significant difference between WT and Prnp^ZH3/ZH3 mice (WT 191 ± 38 (3); Prnp^ZH3/ZH3 244 ± 68 (3); mean ± SEM (n); p = 0.5277; unpaired t-test). (e) EM images of sciatic nerves from WT and Prnp^ZH3/ZH3 mice at 5 d.p.c. showed extensive demyelination and few intact appearing myelin rings (white asterix). Scale bar: 5 μm.