Figure 9.

Recombined PDGFRα+ cells in the PNS do not give rise to P0+ cells in response to peripheral injury. a–c, Four weeks after dorsal root crush (a, b) or sciatic nerve crush injury in PDGFRαCreER:mGFP mice (c), mGFP+ cells had branched and flattened processes extending in the endoneurium between clusters of P0+ myelinating Schwann cells. Twelve weeks after a severe dorsal root crush injury (d), there was no evidence of mGFP+/P0+ Schwann cells in the dorsal root (d′, d″) or the DRG (d‴). Only the injured spinal cord harbored recombined cells expressing both mGFP and P0. (d′, arrows). Images were taken in root or sciatic nerve longitudinal sections (a–c) or spinal cord cross sections (d). Scale bars: d, 200 μm; d′, 50 μm; d‴, 20 μm; a–d″,10 μm.