Regenerated host axons form synapses with neurons derived from neural stem cells transplanted into peripheral nerves.

It is reported that neural stem cells (NSC) can arrest denervated muscle atrophy and promote nerve regeneration when transplanted into injured peripheral nerves, and that regenerated host axons can form synapses with transplanted and differentiated NSC. In this study, F344 rat nerve segments and F344 rat NSC were transplanted into host green fluorescence protein (GFP) transgenic F344 rats. This allowed transplanted F344 rat tissue to be used as a nonluminous background for the clear visualization of regenerated host GFP axons. Regenerated host axons grew into the transplanted F344 nerve segment 2 weeks after nerve anastomosis. Immunohistochemical staining and confocal microscope analysis revealed that regenerated host axons formed synapses with NSC-derived neurons. The findings confirmed that regenerated peripheral axons form synapses with neurons in peripheral nerves, possibly forming the basis for clinical application in peripheral nerve injury.