Embryonic neurons transplanted into the tibial nerve reinnervate muscle and reduce atrophy but NCAM expression persists

Abstract Objective: The aim of this study was to use the glycogen depletion technique to determine whether reinnervated muscle fibers could be distinguished from denervated muscle fibers by their size or by neural cell adhesion molecule (NCAM) expression. Methods: Medial gastrocnemius muscles of five adult Fischer rats were reinnervated from embryonic neurons transplanted into the distal stump of the tibial nerve. Ten weeks later, the transplants were stimulated repeatedly to deplete reinnervated muscle fibers of glycogen. Areas of reinnervated (glycogen-depleted) muscle fibers were measured and assessed for NCAM expression. The areas of muscle fibers from reinnervated, denervated (n=5) and unoperated control muscles (n=5) were compared. Results: Mean reinnervated muscle fiber area was significantly larger than the mean for denervated fibers (mean ± SE: 40 ± 6 and 10 ± 1% of unoperated control fibers, respectively). NCAM was expressed in 55 ± 7% of reinnervated fibers (mean ± SE; range: 42–77%). The mean ...