The Protective Effects of the Acellular Nerve Matrix Allografts on the Motor Neurons of the Anterior Horn of Spinal Cord

Objective To explore the protective effects of the acellular nerve matrix allografts on the motor neurons of the spinal cord. Methods Ten rats were prepared for the acellular matrix grafts of sciatic nerves by chemical extraction, the other rats were divided into the experimental group (sciatic nerve injury bridged by grafts, 10 rats) and the control group (sciatic nerve injury, 10 rats). After three to four months survival, the grafts, L_6~S_1 spinal cord seqments and the gastrocnemius of the operative side of the rats were taken out. All the samples were stained by HE, Nissl and AchE combining silver staining, and were processed for electronic microscopy. The number of the neurons in anterior horn was analyzed statistically. Results Three to four months after transplantation, the operated leg of the experimental group stepped backward powerfully, the toe could separate and walk to normal gradually, the bottom of the operated paw escaped when it was punctured by a needle. The operated leg of the control group didn′t recover in the functions of motor and sense. A large quantity of regenerated nerve fibers with myelin sheath was observed in the graft of the experimental group. The regenerated nerve fiber bunches and motor endplates in the operative gastrocnemius of the experimental group were observed. The number of the anterior lateral group cells of the L_6~S_1 spinal cord in the transplated side of the experimental group and the defect side of the control group was less than that of the normal side, especially the control group. The number of the neurons in the anterior horn of the transplated side of the experimental group was less than that of the normal side and was much more than that of the defect side of the control group (P0.01). Conclusions The acellular nerve matrix allografts had well protective effects on the motor neurons by bridging the defect of the peripheral nerve.