Martin John H
Department of Physiology, Pharmacology & Neuroscience, City University of New York School of Medicine, New York, NY, USA.
Neural Regen Res. 2016 Sep;11(9):1389-1391. doi: 10.4103/1673-5374.191199.
As most spinal cord injuries (SCIs) are incomplete, an important target for promoting neural repair and recovery of lost motor function is to promote the connections of spared descending spinal pathways with spinal motor circuits. Among the pathways, the corticospinal tract (CST) is most associated with skilled voluntary functions in humans and many animals. CST loss, whether at its origin in the motor cortex or in the white matter tracts subcortically and in the spinal cord, leads to movement impairments and paralysis. To restore motor function after injury will require repair of the damaged CST. In this review, I discuss how knowledge of activity-dependent development of the CST-which establishes connectional specificity through axon pruning, axon outgrowth, and synaptic competition among CST terminals-informed a novel activity-based therapy for promoting sprouting of spared CST axons after injur in mature animals. This therapy, which comprises motor cortex electrical stimulation with and without concurrent trans-spinal direct current stimulation, leads to an increase in the gray matter axon length of spared CST axons in the rat spinal cord and, after a pyramidal tract lesion, restoration of skilled locomotor movements. I discuss how this approach is now being applied to a C contusion rat model.
由于大多数脊髓损伤（SCI）是不完全性的，促进神经修复和恢复丧失的运动功能的一个重要目标是促进保留的下行脊髓通路与脊髓运动回路的连接。在这些通路中，皮质脊髓束（CST）在人类和许多动物中与熟练的随意功能最为相关。CST的丧失，无论是在其起源的运动皮层，还是在皮层下和脊髓的白质束中，都会导致运动障碍和瘫痪。损伤后恢复运动功能需要修复受损的CST。在这篇综述中，我讨论了关于CST依赖活动发育的知识——通过轴突修剪、轴突生长以及CST终末之间的突触竞争建立连接特异性——如何为一种新型的基于活动的疗法提供信息，该疗法用于促进成熟动物损伤后保留的CST轴突发芽。这种疗法包括有或没有同时进行经脊髓直流电刺激的运动皮层电刺激，可导致大鼠脊髓中保留的CST轴突的灰质轴突长度增加，并且在锥体束损伤后，恢复熟练的运动。我还讨论了这种方法目前如何应用于C挫伤大鼠模型。
