Motor Recovery after Spinal Cord Injury Enhanced by Strengthening Corticospinal Synaptic Transmission
Motor Recovery after Spinal Cord Injury Enhanced by Strengthening Corticospinal Synaptic Transmission
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DOI：
10.1016/j.cub.2012.10.046
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发表时间：
2012-12-18
期刊：
影响因子：
9.2
通讯作者：
Perez, Monica A.
中科院分区：
文献类型：
--
作者：
Bunday, Karen L.;Perez, Monica A.
皮质脊髓束是动物和人类脊髓损伤（SCI）后运动恢复的重要靶点[1-5]。自主运动输出取决于皮质脊髓轴突和脊髓运动神经元之间的突触的功效，其可以通过神经元尖峰的精确定时来调节[6-8]。使用非侵入性技术，我们制定了量身定制的协议，精确的时间到达下行和外周截击在皮质脊髓运动神经元突触的内在手指肌肉在人类慢性不完全性SCI。我们发现，运动神经元放电前突触前齐射的到来增强了皮质脊髓传递和手部随意运动输出。截击到达和假刺激的相反顺序不影响或减少自主运动输出和电生理结果。这些发现是第一次证明，残留的皮质脊髓运动神经元突触的尖峰时间依赖性可塑性提供了一种机制，以改善SCI后的运动功能。调节残留的皮质脊髓运动神经元突触可能是一种新的治疗靶点，用于增强影响皮质脊髓束的运动障碍的自主运动输出。
The corticospinal tract is an important target for motor recovery after spinal cord injury (SCI) in animals and humans [1-5]. Voluntary motor output depends on the efficacy of synapses between corticospinal axons and spinal motoneurons, which can be modulated by the precise timing of neuronal spikes [6-8]. Using noninvasive techniques, we developed tailored protocols for precise timing of the arrival of descending and peripheral volleys at corticospinal-motoneuronal synapses of an intrinsic finger muscle in humans with chronic incomplete SCI. We found that arrival of presynaptic volleys prior to motoneuron discharge enhanced corticospinal transmission and hand voluntary motor output. The reverse order of volley arrival and sham stimulation did not affect or decreased voluntary motor output and electrophysiological outcomes. These findings are the first demonstration that spike timing-dependent plasticity of residual corticospinal-motoneuronal synapses provides a mechanism to improve motor function after SCI. Modulation of residual corticospinal-motoneuronal synapses may present a novel therapeutic target for enhancing voluntary motor output in motor disorders affecting the corticospinal tract.