Fu Zening, Tu Yiheng, Di Xin, Biswal Bharat B, Calhoun Vince D, Zhang Zhiguo
School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen, China.
The Mind Research Network, Albuquerque, NM, United States.
Front Hum Neurosci. 2017 Dec 7;11:593. doi: 10.3389/fnhum.2017.00593. eCollection 2017.
Functional brain imaging has revealed two types of dynamic patterns of brain in the resting-state: the dynamics of spontaneous brain activities and the dynamics of functional interconnections between spontaneous brain activities. Although these two types of brain dynamics are usually investigated separately in the literature, recent functional magnetic resonance imaging (fMRI) studies have shown that they exhibit similar spatial patterns, suggesting the dynamics of spontaneous brain activities and the dynamics of their interconnections are associated with each other. In this study, we characterized the local blood oxygenation level dependent (BOLD) dynamics and the functional connectivity dynamics (FCD) in the resting-state, and then investigated their between-region associations. Time-varying FC was estimated as time-varying correlation coefficients using a sliding-window method, and the temporal variability of BOLD and time-varying FC were used to quantify the BOLD dynamics and the FCD, respectively. Our results showed that the BOLD dynamics and the FCD exhibit similar spatial patterns, and they are significantly associated across brain regions. Importantly, such associations are opposite for different types of FC (e.g., within-network FCD are negatively correlated with the BOLD dynamics but the between-network FCD are positively correlated with the BOLD dynamics), and they are spatially heterogeneous across brain networks. The identified heterogeneous associations between the BOLD dynamics and the FCD appear to convey related or even distinct information and might underscore the potential mechanism of brain coordination and co-evolution.
自发脑活动的动态变化以及自发脑活动之间功能连接的动态变化。尽管这两种脑动态变化在文献中通常是分开研究的，但最近的功能磁共振成像（fMRI）研究表明它们呈现出相似的空间模式，这表明自发脑活动的动态变化与其连接的动态变化相互关联。在本研究中，我们对静息状态下局部血氧水平依赖（BOLD）动态变化和功能连接动态变化（FCD）进行了特征描述，然后研究了它们在区域间的关联。使用滑动窗口方法将时变功能连接估计为时变相关系数，并分别使用BOLD的时间变异性和时变功能连接来量化BOLD动态变化和FCD。我们的结果表明，BOLD动态变化和FCD呈现出相似的空间模式，并且它们在脑区之间显著相关。重要的是，不同类型的功能连接（例如，网络内FCD与BOLD动态变化呈负相关，而网络间FCD与BOLD动态变化呈正相关）的这种关联是相反的，并且它们在脑网络中在空间上是异质的。所确定的BOLD动态变化和FCD之间的异质关联似乎传达了相关甚至不同的信息，并且可能突出了大脑协调和共同进化的潜在机制。
