Aging reduces experience-induced sensorimotor plasticity. A magnetoencephalographic study
Aging reduces experience-induced sensorimotor plasticity. A magnetoencephalographic study
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DOI：
10.1016/j.neuroimage.2014.10.010
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发表时间：
2015-01-01
期刊：
影响因子：
5.7
通讯作者：
Peigneux, Philippe
中科院分区：
文献类型：
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作者：
Mary, Alison;Bourguignon, Mathieu;Peigneux, Philippe
μ-α和μ-β自发节律的调制反映了初级感觉运动皮层（SM 1）内的可塑性神经变化。使用脑磁图（MEG），我们研究了在学习运动序列后，衰老如何改变经验诱导的可塑性，观察了在执行简单手部运动期间mu节律调制的学习后与学习前的变化。15名年轻人（18-30岁）和14名老年人（65-75岁）右利手健康参与者在两个单独的会议期间同时使用所有四个左手手指（简单运动任务- SMT）进行手势提示按键。在两次SMT会议之后，他们反复练习了5个元素的顺序手指敲击任务（FTT）。在SMT期间计算的Mu功率在覆盖右侧感觉运动区域的18个梯度计上取平均值，并分别在α（9/10/11 Hz）和β（18/20/22 Hz）频带中比较序列学习前后。使用动态统计参数映射（dSPM）定位μ-α和μ-β波段的源功率图。FTT序列在重新测试时的执行速度快于学习阶段结束时的执行速度，表明性能的离线提升。对SMT会话进行的分析显示，与老年参与者相比，年轻人在开始运动后3000-3500 ms的右侧SM学习后反弹增强。源重建表明，两组中μ-β位于中央前回（运动过程），μ-α位于中央后回（躯体感觉过程）。年轻受试者运动后反弹的增强可能反映了SM 1的训练后可塑性变化。训练后调节效应的减少表明衰老大脑的经验依赖性可塑性降低。(C)2014年爱思唯尔公司All rights reserved.
Modulation of themu-alpha andmu-beta spontaneous rhythms reflects plastic neural changes within the primary sensorimotor cortex (SM1). Using magnetoencephalography (MEG), we investigated how aging modifies experience-induced plasticity after learning a motor sequence, looking at post-vs. pre-learning changes in the modulation of mu rhythms during the execution of simple hand movements. Fifteen young (18-30 years) and fourteen older (65-75 years) right-handed healthy participants performed auditory-cued key presses using all four left fingers simultaneously (Simple Movement task - SMT) during two separate sessions. Following both SMT sessions, they repeatedly practiced a 5-elements sequential finger-tapping task (FTT). Mu power calculated during SMT was averaged across 18 gradiometers covering the right sensorimotor region and compared before vs. after sequence learning in the alpha (9/10/11 Hz) and the beta (18/20/22 Hz) bands separately. Source power maps in the mu-alpha and mu-beta bands were localized using Dynamic Statistical Parametric Mapping (dSPM). The FTT sequence was performed faster at retest than at the end of the learning session, indicating an offline boost in performance. Analyses conducted on SMT sessions revealed enhanced rebound after learning in the right SM1, 3000-3500 ms after the initiation of movement, in young as compared to older participants. Source reconstruction indicated that mu-beta is located in the precentral gyrus (motor processes) andmu-alpha is located in the postcentral gyrus (somatosensory processes) in both groups. The enhanced post-movement rebound in young subjects potentially reflects post-training plastic changes in SM1. Age-related decreases in post-training modulatory effects suggest reduced experience-dependent plasticity in the aging brain. (C) 2014 Elsevier Inc. All rights reserved.