短期低频电刺激对长距离陈旧性(8周)周围神经缺损再生能力的影响

The effect of low-frequency electrical stimulation during operation on nerve regeneration in 8-week-delayed defective nerve

目的探索短期低频电刺激对长距离陈旧性(8周)周围神经缺损再生能力的影响。方法切除一段成年雌性SD大鼠左侧坐骨神经,饲养8周后,修剪近、远侧神经断端制成大鼠坐骨神经长距离陈旧性缺损模型。实验组切取对侧正常坐骨神经桥接缺损并施以短期低频电刺激,对照组同样桥接但不予电刺激。根据实验需要继续饲养不同时间后取材,利用神经三色染色、免疫组织化学染色、免疫荧光染色,逆行示踪、电镜观察等组织学方法观察内源性神经因子表达及神经再生情况。结果免疫荧光染色显示实验组内源性神经因子的表达相对较早也较明显,但逆行示踪实验在两组动物中皆观察到类似数量和形态的神经元标记结果,再生神经组织的三色染色、免疫荧光染色及电镜观察等也在两组动物中观察到相似形态的再生神经纤维,未发现实验组相对对照组有更好的神经再生表现,靶肌肉的相对湿重比及运动终板的组织化学染色亦未观察到明显优势。结论术中短期低频电刺激能对缺损超过8周的长距离陈旧性周围神经缺损发挥有限的影响。

Objective The aim of this study was to examine the effect of short-term low-frequency electrical stimulation(SLES)on nerve regeneration of 8-week delayed peripheral nerve injury with a long gap.Methods Left sciatic nerves of adult female Sprague Dawley rats were transected.Next,8-week-delayed defective nerve models were prepared followed by trimming of the nerve stumps.SLES was applied to the experimental group after the nerve defects had been bridged by contralateral normal sciatic nerves.The nerve defects were also bridged without SLES in the control group.After the animals had been fed for different times as required,tissue specimens were harvested to examine expression of endogenous neurotrophic factors and morphological behavior of regenerating nerves through histological techniques such as Meyer’s trichrome staining,immunofluorescent double-staining,retrograde tracing,and electron microscopy.Results Expression levels of endogenous neurotrophins were higher and more rapidly observed following electrical stimulation.No improved performance of nerve regeneration was found in either development of nerve fibers or reinnervation of target organs.Conclusions The ability of SLES to promote nerve regeneration after a long delay(more than 8 weeks)was limited.