The capacity to move is essential for independence and declines with age. Slow movement speed, in particular, is strongly associated with negative health outcomes. Prior research on mobility (herein defined as movement slowness) and aging has largely focused on musculoskeletal mechanisms and processes. More recent work has provided growing evidence for a significant role of the nervous system in contributing to reduced mobility in older adults. In this article, we report four pieces of complementary evidence from behavioral, genetic, and neuroimaging experiments that, we believe, provide theoretical support for the assertion that the basal ganglia and its dopaminergic function are responsible, in part, for age-related reductions in mobility. We report four a posteriori findings from an existing dataset: (1) slower central activation of ballistic force development is associated with worse mobility among older adults; (2) older adults with the Val/Met intermediate catecholamine-O-methyl-transferase (COMT) genotype involved in dopamine degradation exhibit greater mobility than their homozygous counterparts; (3) there are moderate relationships between performance times from a series of lower and upper extremity tasks supporting the notion that movement speed in older adults is a trait-like attribute; and (4) there is a relationship of functional connectivity within the medial orbofrontal (mOFC) cortico-striatal network and measures of mobility, suggesting that a potential neural mechanism for impaired mobility with aging is the deterioration of the integrity of key regions within the mOFC cortico-striatal network. These findings align with recent basic and clinical science work suggesting that the basal ganglia and its dopaminergic function are mechanistically linked to age-related reductions in mobility capacity.

移动能力对于独立至关重要，并且会随着年龄的增长而下降。特别是缓慢的移动速度与负面的健康结果密切相关。先前关于流动性（定义为运动缓慢）和衰老的研究主要集中在肌肉骨骼机制和过程。最近的工作提供了越来越多的证据，证明神经系统在导致老年人行动不便方面发挥着重要作用。在这篇文章中，我们报告了来自行为、遗传和神经影像学实验的四项补充证据，我们相信，这些证据为基底神经节及其多巴胺能功能部分负责与年龄相关的减少的断言提供了理论支持。流动性。我们报告了来自现有数据集的四个后验发现：(1) 较慢的弹道力发展中枢激活与老年人较差的活动能力有关；(2) 具有参与多巴胺降解的 Val / Met 中间儿茶酚胺-O-甲基转移酶 (COMT) 基因型的老年人表现出比纯合子更大的流动性；(3) 一系列下肢和上肢任务的表现时间之间存在中等关系，支持老年人的运动速度是一种类似特质的属性的观点；(4) 内侧或前额叶 (mOFC) 皮质纹状体网络内的功能连接性与活动性测量之间存在关系，这表明随着年龄增长活动性受损的潜在神经机制是 mOFC 内关键区域完整性的恶化皮质纹状体网络。