Protective Effect of Glial Cell Line-Derived Neurotrophic Factor Infused into Cavitas Subarachnoidealis on Spinal Front Corner Motor Neurons

Objective To investigate the effect of exogenous glial cell line-derived neurotrophic factor(GDNF) infused into the cavitas subarachnoidealis on spinal front corner motor neurons after sciatic nerve axotomy.Methods Forty-eight healthy SD rats were randomly divided into 2 groups:NS group and GDNF group.The left sciatic nerve in rats were cut off.And then 0.9% saline and GDNF solution were injected into cavitas subarachnoidealis at L4～6 in NS group and GDNF group,respectively.The rats were sacrificed on postoperative day 4w,8w and 12w respectively.Their specimen of L4～6 spinal cord were taken at different time and sectioned.The Nissl staining in motor neurons were used for counting of motor neurons.Electron microscopic observation and morphometric analysis were performed at 12 weeks after operation.Results In GDNF group the number of motor neurons in spinal front corner higher than that of NS group.The mean axon diameters and mean myeline sheath thickness were significantly better in GDNF group than control group.SFI in GDNF group was lower in NS group.Conclusion The exogenous GDNF infused into the cavitas subarachnoidealis are supposed to protect the degenerated spinal motor neuron from death after sciatic nerve injury,and to encourage the periphery nerve recovery.