Acquisition of motor memory determines the inter-individual variability of learning-induced plasticity in the primary motor cortex
Acquisition of motor memory determines the inter-individual variability of learning-induced plasticity in the primary motor cortex
复制标题
运动记忆的获得决定了初级运动皮层学习诱发的可塑性的个体间差异
DOI：
10.1152/japplphysiol.00470.2018
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发表时间：
2018
影响因子：
3.3
通讯作者：
Funase K
中科院分区：
文献类型：
--
作者：
Hirano M;Kubota S;Koizume Y;Funase K
获得新的运动技能会诱导初级运动皮层（M1）的可塑性重组。先前的研究表明，通过运动技能学习，M1兴奋性增加。然而，这种M1重组在个体之间是高度可变的，即使他们通过相同的训练方案提高了他们的技能表现。为了揭示这种个体间变异的来源，我们研究了记忆引导的前馈运动的获取和学习诱导的M1兴奋性增加之间的关系。28名被试参加了实验1.我们要求受试者学习视觉跟踪任务。受试者控制PC显示器上的光标，通过进行脚踝背屈和跖屈来追踪目标线。在实验1中，我们每六次试验就移除光标移动提供的在线视觉反馈一次，这使我们能够评估受试者是否能够执行准确的记忆引导运动。运动诱发电位（MEP）引起的胫骨前肌经颅磁刺激的相关M1之前和之后的视觉跟踪任务的学习和一半的试验。我们发现，MEP幅度增加沿着与记忆引导的运动的改善。在实验2（n= 10）中，我们通过检查记忆引导运动的改善是否会引起MEP振幅的增加来证实这种关系。这项研究的结果表明，可塑性重组的M1诱导学习的视觉技能与收购的记忆引导movement.NEW &值得注意的新的运动技能的收购增加了兴奋性的初级运动皮层（M1）。我们最近报道，M1兴奋性的增加量在个体之间是高度可变的，即使他们以相似的程度学习了相同的技能，但这种个体间变异性的来源仍然不清楚。本研究表明，这种个体间的差异与个体是否获得运动记忆有关，这使他们能够产生准确的记忆引导运动。
Acquisition of new motor skills induces plastic reorganization in the primary motor cortex (M1). Previous studies have demonstrated the increases in the M1 excitability through motor skill learning. However, this M1 reorganization is highly variable between individuals even though they improve their skill performance through the same training protocol. To reveal the source of this interindividual variability, we examined the relationship between an acquisition of memory-guided feedforward movements and the learning-induced increases in the M1 excitability. Twenty-eight subjects participated inexperiment 1. We asked subjects to learn a visuomotor tracking task. The subjects controlled a cursor on a PC monitor to pursue a target line by performing ankle dorsiflexion and plantar flexion. Inexperiment 1, we removed the online visual feedback provided by the cursor movement once every six trials, which enabled us to assess whether the subjects could perform accurate memory-guided movements. Motor-evoked potentials (MEP) were elicited in the tibialis anterior muscle by transcranial magnetic stimulation of the relevant M1 before and after the learning of the visuomotor tracking task and after half the trials. We found that the MEP amplitude was increased along with the improvement in memory-guided movements. Inexperiment 2(n= 10), we confirmed this relationship by examining whether the improvement in memory-guided movements induces increases in MEP amplitude. The results of this study indicate that the plastic reorganization of the M1 induced by the learning of a visuomotor skill is associated with the acquisition of memory-guided movements.NEW & NOTEWORTHYAcquisition of novel motor skills increases excitability of the primary motor cortex (M1). We recently reported that the amount of increases in the M1 excitability is highly variable between individuals even though they learned the same skill to the similar extent, yet the sources of this interindividual variability still remain unclear. The present study revealed that this interindividual variability is associated with whether individuals acquire a motor memory, which enables them to produce accurate memory-guided movements.