Lurie Daniel J, Pappas Ioannis, D'Esposito Mark
Department of Psychology, University of California, Berkeley.
Department of Neurology, Keck School of Medicine, University of Southern California.
bioRxiv. 2023 Jul 12:2023.07.12.548751. doi: 10.1101/2023.07.12.548751.
Recent years have seen growing interest in characterizing the properties of regional brain dynamics and their relationship to other features of brain structure and function. In particular, multiple studies have observed regional differences in the "timescale" over which activity fluctuates during periods of quiet rest. In the cerebral cortex, these timescales have been associated with both local circuit properties as well as patterns of inter-regional connectivity, including the extent to which each region exhibits widespread connectivity to other brain areas. In the current study, we build on prior observations of an association between connectivity and dynamics in the cerebral cortex by investigating the relationship between BOLD fMRI timescales and the modular organization of structural and functional brain networks. We characterize network community structure across multiple scales and find that longer timescales are associated with greater within-community functional connectivity and diverse structural connectivity. We also replicate prior observations of a positive correlation between timescales and structural connectivity degree. Finally, we find evidence for preferential functional connectivity between cortical areas with similar timescales. We replicate these findings in an independent dataset. These results contribute to our understanding of functional brain organization and structure-function relationships in the human brain, and support the notion that regional differences in cortical dynamics may in part reflect the topological role of each region within macroscale brain networks.
近年来，人们对表征区域脑动力学特性及其与脑结构和功能的其他特征之间的关系越来越感兴趣。特别是，多项研究观察到在静息期间活动波动的“时间尺度”上存在区域差异。在大脑皮层中，这些时间尺度与局部回路特性以及区域间连接模式有关，包括每个区域与其他脑区广泛连接的程度。在当前的研究中，我们通过研究血氧水平依赖性功能磁共振成像（BOLD fMRI）时间尺度与脑结构和功能网络的模块化组织之间的关系，基于之前关于大脑皮层连接性与动力学之间关联的观察结果展开研究。我们在多个尺度上表征网络群落结构，发现较长的时间尺度与群落内更强的功能连接性和多样的结构连接性相关。我们还重复了之前关于时间尺度与结构连接程度之间正相关的观察结果。最后，我们发现具有相似时间尺度的皮层区域之间存在优先功能连接的证据。我们在一个独立的数据集中重复了这些发现。这些结果有助于我们理解人类大脑中的功能性脑组织以及结构 - 功能关系，并支持这样一种观点，即皮层动力学的区域差异可能部分反映了每个区域在宏观尺度脑网络中的拓扑作用。
