Center for Visual and Neurocognitive Rehabilitation, U.S. Department of Veterans Affairs , Decatur, GA , USA ; Department of Neurology, Emory University , Atlanta, GA , USA.
Front Aging Neurosci. 2013 Oct 30;5:66. doi: 10.3389/fnagi.2013.00066. eCollection 2013.
Physical fitness has been long associated with maintenance and improvement of motor performance as we age. In particular, measures of psychomotor speed and motor dexterity tend to be higher in physically fit aging adults as compared to their sedentary counterparts. Using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), we explored the patterns of neural activity that may, in part, account for differences between individuals of varying physical fitness levels. In this study, we enrolled both sedentary and physically fit middle age (40-60) and younger (18-30) adults and measured upper extremity motor performance during behavioral testing. In a follow-up session, we employed TMS and fMRI to assess levels of interhemispheric communication during unimanual tasks. Results show that increased physical fitness is associated with better upper extremity motor performance on distal dexterity assessments and increased levels of interhemispheric inhibition in middle age adults. Further, the functional correlates of changes of ipsilateral activity appears to be restricted to the aging process as younger adults of varying fitness levels do not differ in hemispheric patterns of activity or motor performance. We conclude that sedentary aging confers a loss of interhemispheric inhibition that is deleterious to some aspects of motor function, as early as midlife, but these changes can be mediated by chronic engagement in aerobic exercise.
身体活动与运动表现的维持和改善有着长期的关联，随着年龄的增长而变化。特别是在心理运动速度和运动灵活性方面，与久坐不动的同龄人相比，身体活跃的老年成年人往往表现得更好。我们使用功能磁共振成像（fMRI）和经颅磁刺激（TMS）来探索可能部分解释不同身体活动水平个体之间差异的神经活动模式。在这项研究中，我们招募了久坐不动和身体活跃的中年（40-60 岁）和年轻（18-30 岁）成年人，并在行为测试期间测量了上肢运动表现。在后续的会议中，我们使用 TMS 和 fMRI 评估了单侧任务期间的大脑半球间的交流水平。结果表明，较高的身体活动水平与上肢远端灵巧性评估中的更好的运动表现以及中年成年人大脑半球间抑制水平的提高相关。此外，同侧活动变化的功能相关性似乎仅限于衰老过程，因为不同身体活动水平的年轻成年人在大脑半球活动或运动表现方面没有差异。我们得出结论，久坐不动的衰老会导致大脑半球间抑制的丧失，从而对某些运动功能产生不利影响，这种影响早在中年就会出现，但这些变化可以通过长期进行有氧运动来调节。
