Age-related changes in causal interactions between cortical motor regions during hand grip
Age-related changes in causal interactions between cortical motor regions during hand grip
复制标题
DOI：
10.1016/j.neuroimage.2011.11.025
复制
发表时间：
2012-02-15
期刊：
影响因子：
5.7
通讯作者：
Ward, Nick S.
中科院分区：
文献类型：
--
作者：
Boudrias, Marie-Helene;Goncalves, Carla Sa;Ward, Nick S.
随着年龄的增长，运动表现期间的大脑活动变得更广泛，更少的侧化，以应对正在进行的退行性过程。在这项研究中，我们感兴趣的是，随着年龄的增长，这种活动模式的变化是如何支持运动表现的。我们使用经颅磁刺激（TMS）和功能性磁共振成像（fMRI）来评估等距握力过程中运动系统连通性的年龄相关变化。采用配对脉冲TMS测量右手握力过程中对侧M1 （cM1）到同侧M1 （iM1）的半球间抑制（IHI）变化。采用功能磁共振成像数据的动态因果模型（DCM）研究了年龄对右手握力过程中皮质运动网络因果相互作用的影响。使用贝叶斯模型选择来确定最能解释所有受试者数据的因果模型。首先，我们证实TMS和DCM测量均显示cM1对iM1的抑制作用较弱/促进作用较强。这些值彼此相关，为我们的DCM连接性测量提供了表面有效性。我们发现，随着年龄的增长，(i)在所有同侧皮质运动区域之间，（ii）在两个半球和iM1的皮质运动区域之间，相互促进的影响越来越大。随着年龄的增长，我们的任务表现没有差异，这表明同侧皮质运动区，特别是iM1，通过日益促进的皮质-皮质影响，在维持随着年龄增长的表现水平方面发挥着核心作用。(C) 2011爱思唯尔公司版权所有。
Brain activity during motor performance becomes more widespread and less lateralized with advancing age in response to ongoing degenerative processes. In this study, we were interested in the mechanism by which this change in the pattern of activity supports motor performance with advancing age. We used both transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to assess age related changes in motor system connectivity during isometric hand grip. Paired pulse TMS was used to measure the change in interhemispheric inhibition (IHI) from contralateral M1 (cM1) to ipsilateral M1 (iM1) during right hand grip. Dynamic Causal Modelling (DCM) of fMRI data was used to investigate the effect of age on causal interactions throughout the cortical motor network during right hand grip. Bayesian model selection was used to identify the causal model that best explained the data for all subjects. Firstly, we confirmed that the TMS and DCM measures both demonstrated a less inhibitory/more facilitatory influence of cM1 on iM1 during hand grip with advancing age. These values correlated with one another providing face validity for our DCM measures of connectivity. We found increasing reciprocal facilitatory influences with advancing age (i) between all ipsilateral cortical motor areas and (ii) between cortical motor areas of both hemispheres and iM1. There were no differences in the performance of our task with ageing suggesting that the ipsilateral cortical motor areas, in particular iM1, play a central role in maintaining performance levels with ageing through increasingly facilitatory cortico-cortical influences. (C) 2011 Elsevier Inc. All rights reserved.