Ga-As 레이저광이 가토손상말초신경의 재생능력에 미치는 영향

The effect of Ga-As laser irradiation on the injured peripheralnerve regneration in rabbits

This experimental study was carried out to evaluate the effect of As-Ga laser irradiation on the regeneration of an injured peripheral nerve in rabbits electrophysiologically and through the retrograde axonal transport of horseradish peroxidase(HRP). The experimental animals were divided into a normal group, a laser irradiation group, and a non-irradiation group, and each was subdivided in 1, 3, 5 and 9 week groups according to the time lapsed after the nerve injury. Under general anesthesia, the mandibular branch of the facial nerve was exposed, and a pair of stimulating electrodes and EMG recording electrodes were placed on the trunk of the facial nerve and the orbicularis oris muscle of the lower lip, respectively. After measurement of the threshold intensity of the facial nerve and the recording of the EMG, a crushing injury was given to the nerve. An irradiation by As-Ga laser was performed for 10 minutes everyday for one week. After the experimental period, the electrophysiological parameters were determined again, and a 50% HRP solution was applied to the nerve ending for 72 hours. The numbers of HRP - positive neurons were calculated under a light microscope and the EMG was analyses with a computer. 1. In the 3 and 5 week groups, the numbers of HRP - positive neurons in the facial nucleus were significantly increased in the laser irradiation group. 2. The treshold intensity of the facial nerve significantly increased after nerve injury, and a rapid recovery of the threshold intensity was observed in the laser irrdiation group. 3. However, recovery of the conduction velocity of the injured facial nerve was not significantly different between the laser irradiation groups and the non-irradiation groups.