The purpose of this experiment was to elucidate the influence of the low-energy He-Ne laser on the function of regeneration of peripheral nerve. Forty-four rabbits about 2.5 kg body weight were used in the experiment. The animals were divided into 4, 8, 12, 16 weeks groups according to the observation period. Six animals were used in each irradiated group and in the control group 5 rabbits were used in each observation period. Regeneration of the axon and myelinc sheath, the latent rate of the common peroneal nerve, the conditions of the anterior tibital muscle and the toe expansion test were all observed systematically in both groups. The experimental results was: A few thin regenerated axon was seen at 4 weeks in the irradiated group, while in the control group it might be seen at 8 weeks, the P value was lt; 0.01. A low amplitude latent rate of the common peroneal nerve is determined at the peroneal side of the anterior tibial muscle in a few animal at 4 weeks of the irradiated group, and it is not observed in the control group, from 12 to 16 weeks. THe latent rate of the common peroneal nerve was the irradiated group than in the controlled, the P value was lt; 0.01. The regeneration of the myeline sheath was evident in the irradiated group, and also the slstion of the musdle fibers anterior tibial muscle was clearly visible than the controlled. 16 weeks postoperatively, the toe expansion test was normal in the irradiated group, while in the control group it was the same as seen at 12 weeks after operation in the irradiated group. Now it was certain that the low-energy He-Ne laser could promole the function of the spinal motor nerve cells and accelerate the axonal regeneration.
The object of this experimental study was to investigate the influence of low-energy He-Ne laser on the motor nerve cells of the spinal cord. The experimental study included as follws: (1) Four rabbits were used in this experiment. The L5-6 spinal cord segment was irradiated by He-Ne laser percutaneously, the nerve velocity of the comon peroneal nerve was measured in order to determine the function of the spinal motor nerve cells when the peripheral nerve was intact. (2) The common peroneal nerve was transected on one side wothout repair, two weeks after laser irradiation, the grey mater of the spinal cord of L5-6 segment was procured for electronic microscopic examination. (3) The common peroneal nerve on the contralateral side was transected and followed by end-to-end anastomosis, and laser irradiation was done on the same spinal cord segment. Two weeks after irradiation, the nerve velocity of the common peroneal nerve and the toe expanding test were investigated. The results were: (1) the He-Ne laser can influence the spinal motor nerve cells function as expressed by latent rate when the peripherial nerve is intact. i.e. the nerve velocity is slower than mormal, and the amplitude is markedly decreared. (2) the change of the microstructure of the spinal motor nerve cells is comparatively slight in the 10 and 15 minutes groups. (3) the recovery of the nerve velocity and the toe expansion are more earlier in the 15 min. group. In short, the low-energy He-Ne laser can influence the function of the spinal motor nerve cells.