Figure 5.

Twelve weeks after grafting, the rats were harvested and myelinated axons were labeled with osmium tetroxide.

Transverse sections were taken 3 mm proximal to the graft (first column), in the center of the 10 mm graft (second column), and 3 mm distal to the graft (third column). Micrographs were taken with a Keyence BZ9000 microscope of rats with an isograft and no treatment (NT group) (A), rats treated with MCMs only (B), rats treated with MCMs + NGF (C), rats treated with MCMs + GDNF (D), and rats treated with MCMs + NGF & GDNF (E). Scale bars: 50 µm. For all groups, the axons appeared larger with thick myelination in the proximal sections, compared to both in the graft and distal to the graft where the axons were smaller with a thin layer of myelination. Although, there were no significant differences among the groups in total numbers of axons proximal to the graft (P = 0.6495, one-way ANOVA), in the grafts of rats treated with MCMs + GDNF or the combination of MCMs + NGF & GDNF had significantly more myelinated axons (P < 0.0001, one-way ANOVA) and distal to the graft, only the rats treated with the combination of MCMs + NGF & GDNF had significantly more myelinated axons (P = 0.0005, one-way ANOVA) (F). There were no significant differences between groups in terms of axon size (µm²) proximal to the graft, in the graft, or distal to the graft (G). ***P < 0.001 (one-way ANOVA followed by Tukey’s post hoc test); error bars represent ± SEM; n = 4 per group. ANOVA: Analysis of variance; GDNF: glial cell-derived neurotrophic factor; MCM: mineral coated microparticle; NGF: nerve growth factor.