Protective Effect Of Glial Cell Line-derived Neurotrophic Factor On Spinal Front Corner Motor Neurons After Sciatic Nerve Injury

ObjectiverThe aim of the study was to investigate the effect of exogenous glial cell line-derived neurotrophic factor(GDNF) on spinal front corner motor neurons after sciatic nerve axotomy.MethodrAniamals were divided into 3 groupsifalse operation group,NS and GDNF group.Upon silicone-tubulization of transected sciatic nerve in the adult rat,either 0.9% saline or GDNF solution was injected into the silicone chamber.The rats with left sciatic nerve cuted off were taken as model for treatment by implanting solution. The right sciatic nerve was taken as control. The rats were sacrificed on postoperative 3d,1w,2w,4w,8w and 12w respectively.Their specimen of L4-6 spinal cord were taken at different time and sectioned. The Nissl staining and cholinesterase(ChE) staining in motoneurons were used for counting of motor neurons. The HE staining,and TUNEL technique was used for detection of apoptotic motor neurons What's more, the ultrastructure of the neuron wasobserved. Result: The number of spinal front corner motor neurons decreased 14% of the normal 3 days after sciatic nerve injury,and 40% 3 weeks later.The ChE activity was obvious lower than that in control group. 1 week after the operation the number of TUNEL staining positive spinalord motor neurons was at most,and disappear in 3 weeks.The change of motor neuron ultra-structure include: 3days after the operation there are only some early show of the apoptosis.At the point of 1 weeks later the typical apoptosis cell was detected,at the same time different phases of apoptosis cell can be founded. In GDNF group the number of spinal front corner motor neurons and the ChE activity were notable higher than that of NS group, the number of TUNEL staining positive spinal motor neurons was decreased.Conclusion: 1, Apoptosis of spinal motor neurons can be induced by transction of sciatic nerve in adult rats.2,The number of spinal front corner motor neurons was decreased and the ChE activity was sliped after transction of sciatic nerve.3,The exogenous GDNF was capable of protecting motor nuron from death induced by peripheral nerve injury.