Reinnervation of Paralyzed Muscle by Nerve-Muscle-Endplate Band Grafting

Our immediate reinnervation experiments have demonstrated that NMEG-NMZ technique resulted in optimal functional recovery, extensive axonal regeneration and endplate reinnervation. However, it remains unknown if this method has the potential for delayed muscle reinnervation. In the past year, we performed long-term (3, 6, and 9 months) denervation experiments to determine the denervation-induced neuromuscular alterations. Our results showed that prolonged denervation resulted in a progressive reduction of muscle mass and myofiber size. In the denervated muscles, normal axons almost disappeared, whereas MEPs were still detected in 9-month-denervated muscles, indicating that MEPs are more stable when compared with nerve axons after denervation. Preservation of the original MEPs in the denervated muscle favors reinnervation with NMEG-NMZ. We subsequently performed delayed (3-month delay) reinnervation experiments. Our data showed that NMEG-NMZ resulted in satisfactory recovery of muscle mass (82% of the control), axon counts (74%), and functional recovery (79% of control).