生物素葡聚糖胺观测周围神经局部轴突运输的实验研究

目的 研究神经示踪剂生物素葡聚糖胺（BDA）用于直观观察周围神经局部轴突运输的可行性。方法 （1）显露双侧兔坐骨神经，于实验侧及对照侧坐骨神经干注射不同浓度、不同剂量BDA，对照侧注射生理盐水，术后6、12、24、48h取样。于光镜及共聚焦显微镜下观察样本。（2）将兔左侧坐骨神经横断损伤并缝合，分别于术后1～6周于损伤近侧神经干注射10％BDA，12h后取标本观察。结果 10％BDA可清晰地在周围神经轴突内显像，操作简单，结果易于观察。同时，坐骨神经断伤术后3周时有明确的轴浆运输的恢复。结论 BDA神经干局部注射后能较清楚而直观地显示局部轴突运输的情况。

Biotinylated dextran amine (BDA) for observing the local axonal transport in rabbit sciatic nerve: An experimental study

s Objective To study the possibility of botinylated dextran amine (BDA) observing the local axinal transport of peripheral nerve and the changes of axoplasm in traumatic injured sciatic nerve.Methods BDA was injected into the sciatic nerve trunk of 24 adult rabbits by a microsyringe with different concentrations and different volume,and saline was injected into the matched control nerve.The sciatic nerve was sampled after a survival period of 6 to 48 h and observed under the light microscope and confocal microscopy.One,2,3,4,6 weeks after adult rabbit sciatic nerve transected injury,10% BDA solution was injected into the sciatic nerve trunk by a microsyringe proximal to the injury site.The sciatic nerve was sampled following pressure injection of BDA with survival time of 12 h,and the sections were directly examined under microscopy and confocal microscopy.Results Light microscopy:In the BDA injected region,positive labeled nerve fiber was stained with brown and purpl substance.Both myelin sheath and axis-cylinder were stained.No positive stained fiber could be detected in matched control nerve.Positive stained fiber could be viewed after 6 h following injection of 10% BDA solution in the proximal to the ligation of sciatic nerve.Confocal microscopy:After 6 h following injection of BDA,in the area proximal to the ligation,the axis-cylinder was brightly labeled while the myelin sheath was fluorescenced weakly.Up to three weeks and afterwords,in injuryed sciatic nerves stained fiber proximal to the ligation could be detected clearly under light microscopy and confocal microscopy.Conclusion The use of neural tracer BDA permits the directly identification of labeled axonal transport of sciatic nerve without difficult processing.Axonal transport was recruited after 3 weeks in break-fiber injured nerve when proximal and distal nerve stumps were kept intact.