Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
Cereb Cortex. 2021 Jul 29;31(9):3986-4005. doi: 10.1093/cercor/bhab064.
The brain exhibits highly organized patterns of spontaneous activity as measured by resting-state functional magnetic resonance imaging (fMRI) fluctuations that are being widely used to assess the brain's functional connectivity. Some evidence suggests that spatiotemporally coherent waves are a core feature of spontaneous activity that shapes functional connectivity, although this has been difficult to establish using fMRI given the temporal constraints of the hemodynamic signal. Here, we investigated the structure of spontaneous waves in human fMRI and monkey electrocorticography. In both species, we found clear, repeatable, and directionally constrained activity waves coursed along a spatial axis approximately representing cortical hierarchical organization. These cortical propagations were closely associated with activity changes in distinct subcortical structures, particularly those related to arousal regulation, and modulated across different states of vigilance. The findings demonstrate a neural origin of spatiotemporal fMRI wave propagation at rest and link it to the principal gradient of resting-state fMRI connectivity.
大脑表现出高度组织化的自发性活动模式，这些模式可以通过静息态功能磁共振成像（fMRI）波动来测量，这些波动正被广泛用于评估大脑的功能连接。一些证据表明，时空相干波是自发活动的核心特征，它塑造了功能连接，尽管由于血液动力学信号的时间限制，使用 fMRI 很难确定这一点。在这里，我们研究了人类 fMRI 和猴子脑电图中的自发波结构。在这两种物种中，我们都发现了清晰、可重复且具有方向约束的活动波沿着一个空间轴传播，该轴大约代表了皮质的分层组织。这些皮质传播与皮质下结构中不同的活动变化密切相关，特别是与觉醒调节相关的结构，并且在不同的警觉状态下发生调制。这些发现证明了静息状态下 fMRI 波传播的神经起源，并将其与静息状态 fMRI 连接的主要梯度联系起来。
