OBJECTIVE Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P  lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P  lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.

Citation： ZHU Jin,yu,HUANG Yao tian,LU Rong,et al.. MORPHOLOGICAL CHANGES AND ELECTROPHYSIOLOGICAL STUDY OF MOTOR NEURON OF SPINAL CORD FOLLOWING DELAYED REPAIR OF PERIPHERAL NERVE INJURY. Chinese Journal of Reparative and Reconstructive Surgery, 1999, 13(2): 114-118. doi: Copy