Effects of PN graft transplantation and VR re-implantation on the survival of host motoneurons as revealed by neutral red staining at 6 weeks after root avulsion. (A) Normal animals. (B) Animals receiving root avulsion only. (C) Animals receiving PN graft transplantation. (D) Animals receiving VR re-implantation. (a, b, c, and d) Micrographs made under higher magnification of the areas of interest in A, B, C, and D, respectively. (E) PN graft transplantation or VR re-implantation significantly increased the survival rate of motoneurons compared to controls. Furthermore, the survival rate of motoneurons in the animals receiving VR re-implantation was significantly higher than that seen in the animals receiving PN graft transplantation (*: p < 0.001 compared to PN or VR implantation; #: p < 0.05 compared to PN implantation; scale bar: 300 μm in A, B, C and D; 100 μm in a, b, c and d).