Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich Heine University Düsseldorf Düsseldorf, Germany.
Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University Düsseldorf Düsseldorf, Germany ; Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Jülich Jülich, Germany.
Front Aging Neurosci. 2014 Jul 23;6:178. doi: 10.3389/fnagi.2014.00178. eCollection 2014.
Healthy aging is associated with decline in basic motor functioning and higher motor control. Here, we investigated age-related differences in the brain-wide functional connectivity (FC) pattern of the subthalamic nucleus (STN), which plays an important role in motor response control. As earlier studies revealed functional coupling between STN and basal ganglia, which both are known to influence the conservativeness of motor responses on a superordinate level, we tested the hypothesis that STN FC with the striatum becomes dysbalanced with age. To this end, we performed a seed-based resting-state analysis of fMRI data from 361 healthy adults (mean age: 41.8, age range: 18-85) using bilateral STN as the seed region of interest. Age was included as a covariate to identify regions showing age-related changes of FC with the STN seed. The analysis revealed positive FC of the STN with several previously described subcortical and cortical regions like the anterior cingulate and sensorimotor cortex, as well as not-yet reported regions including central and posterior insula. With increasing age, we observed reduced positive FC with caudate nucleus, thalamus, and insula as well as increased positive FC with sensorimotor cortex and putamen. Furthermore, an age-related reduction of negative FC was found with precuneus and posterior cingulate cortex. We suggest that this reduced de-coupling of brain areas involved in self-relevant but motor-unrelated cognitive processing (i.e. precuneus and posterior cingulate cortex) from the STN motor network may represent a potential mechanism behind the age-dependent decline in motor performance. At the same time, older adults appear to compensate for this decline by releasing superordinate motor control areas, in particular caudate nucleus and insula, from STN interference while increasing STN-mediated response control over lower level motor areas like sensorimotor cortex and putamen.
健康老龄化与基本运动功能的下降和更高的运动控制能力有关。在这里，我们研究了与年龄相关的丘脑底核（STN）脑功能连接（FC）模式的差异，STN 在运动反应控制中起着重要作用。由于早期的研究揭示了 STN 与基底节之间的功能耦合，而基底节都已知会在更高的水平上影响运动反应的保守性，我们测试了这样的假设，即 STN 与纹状体的 FC 随着年龄的增长而失去平衡。为此，我们使用双侧 STN 作为种子感兴趣区，对 361 名健康成年人（平均年龄：41.8 岁，年龄范围：18-85 岁）的 fMRI 数据进行了基于种子的静息状态分析。将年龄作为协变量，以确定与 STN 种子的 FC 随年龄变化相关的区域。分析结果显示，STN 与几个先前描述的皮质下和皮质区域（如前扣带回和感觉运动皮层）具有正 FC，还包括一些尚未报道的区域，包括中央和后岛叶。随着年龄的增长，我们观察到与尾状核、丘脑和岛叶的正 FC 减少，与感觉运动皮层和壳核的正 FC 增加。此外，还发现与后扣带回和楔前叶的负 FC 随年龄相关减少。我们认为，与 STN 运动网络相关的自我相关但与运动无关的认知处理（即楔前叶和后扣带回）的脑区的这种去耦减少，可能代表运动表现随年龄下降的潜在机制。与此同时，老年人似乎通过释放与 STN 干扰相关的高级运动控制区域，特别是尾状核和岛叶，同时增加对感觉运动皮层和壳核等较低水平运动区域的 STN 介导的反应控制，来补偿这种下降。
