神经干细胞移植对大鼠脊髓损伤后皮质脊髓束神经元和皮层体感诱发电位的影响

Effects of neural stem cells transplantation on corticospinal tract neurons and cortical somatosensory evoked potentials of rats after spinal cord injury

目的:研究神经干细胞(NSCs)移植对大鼠脊髓损伤(SCI)后皮质脊髓束神经元和皮层体感诱发电位(CSEP)的影响。方法:40只SD大鼠随机分为正常对照组(Normal组)、脊髓损伤组(SCI组)、神经干细胞组(NSC组)、神经干细胞标记组(BrdU+NSCs组)。采用电控脊髓损伤打击装置制作模型,5-溴脱氧尿嘧啶核苷(BrdU)法标记处于对数生长期的NSCs,SCI后即刻进行NSCs移植。免疫组化法观察BrdU标记NSCs的存活、迁移,CSEP监测大鼠神经电生理的变化。用辣根过氧化物酶(HRP)逆行示踪技术标记皮质脊髓束神经元并用四甲基联苯胺(TMB)呈色反应显示皮质脊髓束神经元的存活情况。结果:BrdU+NSCs组在SCI区域可检测到BrdU标记的阳性NSCs,HRP标记皮质脊髓束神经元数目较SCI组明显增多(P<0.05),CSEP-P波潜伏期比SCI组明显缩短(P<0.05)。HRP标记皮质脊髓束神经元数目与CSEP-P波潜伏期变化呈负相关(r=-0.914,P<0.001)。BrdU+NSCs组与NSC组之间比较差异无显著性(P>0.05)。结论:体外培养的胚胎大鼠NSCs可在SCI区域存活、迁移,并可减轻皮质脊髓束神经元的逆行性损伤、缩短SCI后CSEP-P波潜伏期,从而促进大鼠瘫痪肢体功能的恢复。

Objective To study the effects of neural stem cells （NSCs） transplantation on corticospinal tract neurons and cortical somatosensory evoked potentials （CSEP） of rats after spinal cord injury （SCI）. Methods 40 SD rats were randomly divided into 4 groups ： normal group, SCI group, NSCs group, and BrdU＋NSCs group. Rat models with SCI were induced by electrocircuit control spinal cord injuring device. NSCs in logarithmic phage were labeled with BrdU, and the NSCs were transplanted into the injured site after SCI. The survival and immigration of BrdU labeled NSCs were detected by immunohistochemisty, and the function recovery of spinal cord was valued with CSEP. Cortieospinal tract neurons were labeled by retrograde transport of the horseradish peroxidase （HRP） from the lesion site, and the survival of corticospinal tract neurons were shown by tetramethylbenzidine （TMB） reaction. Results BrdU labeled NSCs were detected in the spinal cord after transplantation in BrdU＋NSCs group, in which the number of corticospinal tract neurons labeled by HRP was more than that in SCI group （P 〈 0.05）, and the latency of CSEP-P wave was obviously shortened （P 〈 0.05）. There was a negative correlation between the number of eorticospinal tract neurons labeled by HRP and the latency of CSEP-P wave （r = -0.914, P 〈 0.001）. There was no significant difference of these index between NSCs group and BrdU＋NSCs group （P 〉 0.05）. Conclusions The transplanted NSCs can survive in the injured site of spinal cord, protect corticospinal tract neurons, and shorten the latency of CSEP-P wave, through which can promote more remarkably functional recovery of hind limb in rats after SCI.