Aging of human supraspinal locomotor and postural control in fMRI
Aging of human supraspinal locomotor and postural control in fMRI
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DOI：
10.1016/j.neurobiolaging.2010.09.022
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发表时间：
2012-06-01
影响因子：
4.2
通讯作者：
Jahn, Klaus
中科院分区：
文献类型：
--
作者：
Zwergal, Andreas;Linn, Jennifer;Jahn, Klaus
站立、行走和跑步是儿童时期发展起来的感觉运动任务。之后，它们会自动发挥作用，这是控制脊柱模式产生器的椎上网络的结果。本研究利用功能磁共振成像（fMRI）研究了正常人在运动和站立的心理意象过程中脊柱上运动和姿势网络的年龄依赖性变化。60名健康受试者（年龄：24-78岁）接受了完整的神经、神经眼科和感觉检查，以排除平衡和步态障碍，他们接受了躺、站、走和跑等条件的训练，以便在仰卧时闭上眼睛，在磁共振成像（MRI）扫描仪上按指令想象这些条件，时间为20秒。运动和站立时的血氧水平依赖性（BOLD）信号变化与年龄无关：(1)辅助运动区、尾状核、视觉皮质区、小脑皮层和旁皮层显著激活；(2)运动过程中前庭多感觉皮质区（后岛、顶岛前庭回、颞上回）和前扣带明显失活。运动和站立时大脑激活的以下差异与年龄相关：多感觉前庭皮层、运动敏感视觉皮层（MT/V5）和体感皮层（右侧中央后回）的BOLD信号相对增加。在老年人中，这种多感官激活在站立时最为突出，在步行时较少，在跑步时最少。综上所述，包括前额叶皮质、基底神经节、脑干和小脑运动中枢在内的基本运动和姿势网络的功能激活在老年人中得以保留。研究发现，运动和站立过程中大脑激活的年龄依赖性主要表现在两个方面：运动和站立过程中感觉系统之间皮层抑制性相互作用的机制随着年龄的增长而下降；因此，运动和站立的多感觉皮质控制随着年龄的增长而增强。这些发现可能表明老年人更有意识的运动和姿势策略。(C) 2012爱思唯尔公司版权所有。
Standing, walking, and running are sensorimotor tasks that develop during childhood. Thereafter they function automatically as a result of a supraspinal network that controls spinal pattern generators. The present study used functional magnetic resonance imaging (fMRI) to investigate age-dependent changes in the supraspinal locomotor and postural network of normal subjects during mental imagery of locomotion and stance. Sixty healthy subjects (ages: 24-78 years), who had undergone a complete neurological, neuro-ophthalmological, and sensory examination to rule out disorders of balance and gait, were trained for the conditions lying, standing, walking, and running in order to imagine these conditions on command in 20-second sequences with the eyes closed while lying supine in an magnetic resonance imaging (MRI) scanner. The following blood oxygen level-dependent (BOLD) signal changes during locomotion and stance were found to be independent of age: (1) prominent activations in the supplementary motor areas, the caudate nuclei, visual cortical areas, vermal, and paravermal cerebellum; (2) significant deactivations in the multisensory vestibular cortical areas (posterior insula, parietoinsular vestibular gyrus, superior temporal gyrus), and the anterior cingulate during locomotion. The following differences in brain activation during locomotion and stance were age-dependent: relative increases in the cortical BOLD signals in the multisensory vestibular cortices, motion-sensitive visual cortices (MT/V5), and somatosensory cortices (right postcentral gyrus). In advanced age this multisensory activation was most prominent during standing, less during walking, and least during running. In conclusion, the functional activation of the basic locomotor and postural network, which includes the prefrontal cortex, basal ganglia, brainstem, and cerebellar locomotor centers, is preserved in the elderly. Two major age-dependent aspects of brain activation during locomotion and stance were found: the mechanism of cortical inhibitory reciprocal interaction between sensory systems during locomotion and stance declines in advanced age; and consequently, multisensory cortical control of locomotion and stance increases with age. These findings may indicate a more conscious locomotor and postural strategy in the elderly. (C) 2012 Elsevier Inc. All rights reserved.