Huo Congcong, Zhang Ming, Bu Lingguo, Xu Gongcheng, Liu Ying, Li Zengyong, Sun Lingling
Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, China.
Department of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong Kong.
Front Hum Neurosci. 2018 Mar 16;12:98. doi: 10.3389/fnhum.2018.00098. eCollection 2018.
This study aims to assess the posture-related changes in frequency-specific effective connectivity (EC) in elderly subjects by coupling function measured using functional near-infrared spectroscopy (fNIRS). The fNIRS signals were continuously recorded from the bilateral prefrontal cortex (PFC), motor cortex (MC), and occipital lobe (OL) in 17 healthy elderly and 19 healthy young subjects during sitting and standing states. EC was calculated based on Dynamic Bayesian inference in one low frequency interval I: 0.052-0.145 Hz and one very low frequency interval II: 0.021-0.052 Hz. Results show that in response to posture change, the coupling strength significantly increased in interval I of the young group from right PFC to MC ( < 0.05). Meanwhile, the coupling strength of the elderly group was significantly increased in interval II from the left PFC to right PFC ( = 0.008) and to left MC ( = 0.031) in the standing state as compared with that in the sitting state. Compared with that of the young group, the coupling strength of the elderly group was significantly decreased ( < 0.05) between the right PFC and left PFC in interval I and from PFC and OL to MC in interval II during the sitting state. The decreased EC in interval I was also positively correlated with cognitive scores in the elderly group. In addition, the coupling strength from MC to PFC in interval II during standing state was significantly increased in elderly subjects as compared with that in the young group. These results revealed the age-related changes in reorganization of interregional interactions for different postures. These findings may provide evidence of impaired cognitive function in the elderly and can deepen the understanding on age-related changes in neurovascular coupling.
本研究旨在通过使用功能近红外光谱（fNIRS）测量的耦合功能，评估老年受试者特定频率有效连接性（EC）与姿势相关的变化。在17名健康老年人和19名健康年轻人处于坐姿和站姿时，连续记录双侧前额叶皮质（PFC）、运动皮质（MC）和枕叶（OL）的fNIRS信号。基于动态贝叶斯推理，在一个低频区间I：0.052 - 0.145Hz和一个极低频区间II：0.021 - 0.052Hz计算EC。结果表明，随着姿势变化，年轻组在区间I中从右侧PFC到MC的耦合强度显著增加（P < 0.05）。同时，与坐姿相比，老年组在区间II中，站立状态下从左侧PFC到右侧PFC（P = 0.008）以及到左侧MC（P = 0.031）的耦合强度显著增加。与年轻组相比，老年组在坐姿时区间I中右侧PFC和左侧PFC之间以及区间II中从PFC和OL到MC的耦合强度显著降低（P < 0.05）。老年组在区间I中降低的EC也与认知得分呈正相关。此外，与年轻组相比，老年受试者在站立状态下区间II中从MC到PFC的耦合强度显著增加。这些结果揭示了不同姿势下区域间相互作用重组的年龄相关变化。这些发现可能为老年人认知功能受损提供证据，并可加深对神经血管耦合年龄相关变化的理解。
