Toledo Diana R, Barela José A, Manzano Gilberto M, Kohn André F
Neuroscience Program and Biomedical Engineering Laboratory, University of São Paulo, EPUSP, PTC, São Paulo, Brazil.
Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, São Paulo, Brazil; Institute of Biosciences, São Paulo State University, Rio Claro, Brazil.
Neurosci Lett. 2016 May 27;622:1-5. doi: 10.1016/j.neulet.2016.04.028. Epub 2016 Apr 13.
The aim of this work was to compare cortical beta oscillatory activity between young (YA) and older (OA) adults during the assessment of ankle proprioception. We analyzed the response time (RT) to kinesthetic perception and beta event-related desynchronization/synchronization (ERD/ERS) in response to passive ankle movement applied at a slow speed, 0.5°/s. The relationship between ERD/ERS and RT was investigated by classifying the signals into fast-, medium-, and slow-RT. The results showed a temporal relationship between beta oscillation changes and RT for both groups, i.e., earlier ERD and ERS were obtained for trials with faster response time. ERD was larger and delayed in OA compared to the YA, and beta ERS was present only for OA. These findings suggest that a less efficient proprioceptive signaling reaching the brain of OA requires a higher level of brain processing and hence the differences in ERD potentials between YA and OA. Furthermore, the occurrence of ERS in OA might represent a compensatory strategy of active cortical resetting for adequate sensorimotor behavior due to the age-related reduced peripheral input and neuromuscular impairments. Altered balance between excitatory and inhibitory intracortical activity in older adults presumably explains the changes in beta oscillations.
这项工作的目的是在评估踝关节本体感觉期间，比较年轻成年人（YA）和老年人（OA）之间的皮质β振荡活动。我们分析了对动觉感知的反应时间（RT）以及对以0.5°/秒的慢速施加的被动踝关节运动的β事件相关去同步化/同步化（ERD/ERS）。通过将信号分类为快速、中等和慢速反应时间，研究了ERD/ERS与RT之间的关系。结果显示，两组的β振荡变化与RT之间存在时间关系，即反应时间越快的试验，ERD和ERS出现得越早。与YA相比，OA的ERD更大且延迟，并且β ERS仅在OA中出现。这些发现表明，到达OA大脑的本体感觉信号效率较低，需要更高水平的大脑处理，因此YA和OA之间的ERD电位存在差异。此外，OA中ERS的出现可能代表了一种主动皮质重置的补偿策略，以实现适当的感觉运动行为，这是由于与年龄相关的外周输入减少和神经肌肉损伤所致。老年人皮质内兴奋和抑制活动之间的平衡改变可能解释了β振荡的变化。
