| The basis for poor motor recovery after delayed nerve repair is poorly understood. The present experiments examined the effects of immediate nerve implantation onto muscle surface, prolonged motoneurone axotomy and prolonged muscle and intramuscular nerve sheath denervation on nerve regeneration and muscle reinnervation in the rat. Either tibial motoneurones were axotomized or the distal common peroneal nerve sheath and tibialis anterior muscle were denervated for 0 to 365 days. Nerve regeneration was initiated by suture of proximal tibial nerve stump either to the distal common peroneal stump or directly onto denervated muscle surface. At least 6 months later, nerve regeneration and muscle reinnervation were quantified by means of electrophysiological and histochemical methods. After immediate nerve-muscle suture fewer motor units were reinnervated than after nerve-nerve suture. The number of reinnervated motor units also decreased significantly after prolonged motoneurone axotomy and further decreased after prolonged (... |
