Motor function recovery during peripheral nerve multiple regeneration.

Neuronal functional compensation and multiple regenerating axon sprouting occur during peripheral nerve regeneration. Sprouting nerve buds were quantitatively maintained and had matured when multiple injured distal nerves were anastomosed to smaller number of proximal nerve stumps; this has positive clinical significance for proximal stump damage. This study investigated whether sprouting axon buds would reinnervate the distal neuromuscular junction and maintain the function of the target organ under compensation conditions. The results showed that the sprouting axon buds maintained the numbers and morphology of motor end plates repaired by a smaller number of proximal nerve stumps, and recovered 80.0% tetanic muscle force compared with the normal side. Meanwhile, nerve conduction velocity, compound muscle action potential and diameter of muscular fibres declined 72.7%, 73.2% and 61.8%, respectively, compared with normal. This observation indicates the potential functional reserve of neurons and that it is feasible to repair nerve fibre injury through anastomosis of multiple distal nerve stumps with a smaller number of proximal nerve stumps, within the limits of compensation.