Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Clin Neurophysiol. 2010 Jan;121(1):90-3. doi: 10.1016/j.clinph.2009.07.048. Epub 2009 Nov 11.
To test whether the normal aging itself may change the cortical plasticity in human.
Motor-evoked potentials (MEPs) were measured from 48 right-handed healthy volunteers (age 21-79) before and after the paired associative stimulation (PAS), comprising a single electric stimulus to the right median nerve at wrist and subsequent transcranial magnetic stimulation (TMS) of the left primary motor cortex.
The magnitude of MEP increased by PAS in the young and middle but not in the elderly and its change was negatively correlated with the age.
These results suggest that the human M1 shows age-dependent reduction of cortical plasticity.
The reduction of the M1 plasticity may be caused by the attenuated responsiveness of intracortical circuits in the M1 and/or disrupted sensorimotor integration within basal ganglia-thalamocortical loop.
测试正常衰老本身是否会改变人类大脑皮质的可塑性。
对 48 名右利手健康志愿者（年龄 21-79 岁）进行运动诱发电位（MEPs）测量，在对右侧正中神经腕部进行单次电刺激后和随后对左侧初级运动皮层进行经颅磁刺激（TMS）之前和之后。
年轻和中年人群的 MEPs 在经过 PAS 后会增加，但老年人则不会，并且其变化与年龄呈负相关。
这些结果表明，人类 M1 表现出与年龄相关的皮质可塑性降低。
M1 可塑性的降低可能是由于 M1 内皮质回路的反应性减弱以及基底节-丘脑-皮质回路内感觉运动整合的破坏所致。
