Division of Neurosurgery, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta Hospital, Edmonton, Alberta, Canada.
Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
J Neurosci Res. 2018 May;96(5):852-862. doi: 10.1002/jnr.24209. Epub 2017 Dec 14.
Electrical stimulation (ES) to promote corticospinal tract (CST) repair after spinal cord injury (SCI) is underinvestigated. This study is the first to detail intracortical ES of the injured CST. We hypothesize that cortical ES will promote CST collateralization and regeneration, prevent dieback, and improve recovery in an SCI rat model. The CST was transected at the the fourth cervical level in adult female Lewis rats trained in a stairwell grasping task. Animal groups included (a) ES333 (n = 14; 333 Hz, biphasic pulse for 0.2-ms duration every 500 ms, 30 pulses per train); (b) ES20 (n = 14; 20 Hz, biphasic pulse for 0.2-ms duration every 1 s, 60 pulses per train); (c) SCI only (n = 10); and (d) sham (n = 10). ES of the injured forelimb's motor cortex was performed for 30 min immediately prior to SCI. Comparisons between histological data were performed with a 1-way ANOVA or Kruskal-Wallis test, and grasping scores were compared using repeated-measures 2-way ANOVA. Significantly more axonal collateralization was found in ES333 animals compared with controls (p < .01). Axonal dieback analysis revealed ES20 rats to have consistently more dieback than the other groups at all points measured (p < .05). No difference in axonal regeneration was found between groups, nor was there any difference in functional recovery. Cortical ES of the injured CST results in increased collateral sprouting and influences neuroplasticity depending on the ES parameters used. Further investigation regarding optimal parameters and its functional effects is required.
电刺激（ES）促进脊髓损伤（SCI）后皮质脊髓束（CST）修复的研究还不够深入。本研究首次详细描述了损伤 CST 的皮质内 ES。我们假设皮质 ES 将促进 CST 侧支化和再生，防止逆行性萎缩，并改善 SCI 大鼠模型的恢复。在接受楼梯抓握任务训练的成年雌性 Lewis 大鼠的第四颈椎水平横断 CST。动物组包括：（a）ES333（n=14；333 Hz，双相脉冲持续 0.2 ms，每 500 ms 脉冲一次，每次训练 30 个脉冲）；（b）ES20（n=14；20 Hz，双相脉冲持续 0.2 ms，每 1 s 脉冲一次，每次训练 60 个脉冲）；（c）仅 SCI（n=10）；和（d）假手术（n=10）。在 SCI 前立即对受伤前肢运动皮层进行 30 分钟的 ES。使用单向方差分析或 Kruskal-Wallis 检验对组织学数据进行比较，使用重复测量 2 方式方差分析对抓握评分进行比较。与对照组相比，ES333 动物的轴突侧支化明显更多（p<.01）。轴突逆行性萎缩分析表明，ES20 大鼠在所有测量点的萎缩程度均明显高于其他组（p<.05）。各组之间的轴突再生没有差异，功能恢复也没有差异。受伤 CST 的皮质 ES 导致更多的侧支发芽，并根据使用的 ES 参数影响神经可塑性。需要进一步研究最佳参数及其功能影响。
