Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Belgium.
Biomedical MRI Unit, Department of Imaging & Pathology, Group Biomedical Sciences, KU Leuven, Belgium.
Neuroimage. 2019 Nov 15;202:116050. doi: 10.1016/j.neuroimage.2019.116050. Epub 2019 Jul 23.
Aging is associated with gradual alterations in the neurochemical characteristics of the brain, which can be assessed in-vivo with proton-magnetic resonance spectroscopy (H-MRS). However, the impact of these age-related neurochemical changes on functional motor behavior is still poorly understood. Here, we address this knowledge gap and specifically focus on the neurochemical integrity of the left sensorimotor cortex (SM1) and the occipital lobe (OCC), as both regions are main nodes of the visuomotor network underlying bimanual control. H-MRS data and performance on a set of bimanual tasks were collected from a lifespan (20-75 years) sample of 86 healthy adults. Results indicated that aging was accompanied by decreased levels of N-acetylaspartate (NAA), glutamate-glutamine (Glx), creatine + phosphocreatine (Cr) and myo-inositol (mI) in both regions, and decreased Choline (Cho) in the OCC region. Lower NAA and Glx levels in the SM1 and lower NAA levels in the OCC were related to poorer performance on a visuomotor bimanual coordination task, suggesting that NAA could serve as a potential biomarker for the integrity of the motor system supporting bimanual control. In addition, lower NAA, Glx, and mI levels in the SM1 were found to be correlates of poorer dexterous performance on a bimanual dexterity task. These findings highlight the role for H-MRS to study neurochemical correlates of motor performance across the adult lifespan.
衰老是与大脑神经化学特征的逐渐改变相关的，这些改变可以通过质子磁共振波谱（H-MRS）在体内进行评估。然而，这些与年龄相关的神经化学变化对功能性运动行为的影响仍知之甚少。在这里，我们解决了这一知识空白，并特别关注左感觉运动皮层（SM1）和枕叶（OCC）的神经化学完整性，因为这两个区域都是双上肢控制所基于的视觉运动网络的主要节点。从一个跨年龄段（20-75 岁）的 86 名健康成年人样本中收集了 H-MRS 数据和一系列双上肢任务的表现。结果表明，随着年龄的增长，两个区域的 N-乙酰天冬氨酸（NAA）、谷氨酸-谷氨酰胺（Glx）、肌酸+磷酸肌酸（Cr）和肌醇（mI）水平降低，OCC 区域的胆碱（Cho）水平降低。SM1 中的 NAA 和 Glx 水平降低以及 OCC 中的 NAA 水平降低与视觉运动双上肢协调任务表现较差有关，表明 NAA 可能作为支持双上肢控制的运动系统完整性的潜在生物标志物。此外，SM1 中的 NAA、Glx 和 mI 水平降低与双上肢灵巧性任务的灵巧性能较差相关。这些发现强调了 H-MRS 在研究整个成年期运动表现的神经化学相关性方面的作用。
