Department of Physics, Centre for Nonlinear Studies and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong, People's Republic of China.
The HKBU Institute of Research and Continuing Education, Shenzhen 518000, People's Republic of China.
J Neurosci. 2021 Apr 21;41(16):3665-3678. doi: 10.1523/JNEUROSCI.0623-20.2021. Epub 2021 Mar 16.
Cortical circuits generate patterned activities that reflect intrinsic brain dynamics that lay the foundation for any, including stimuli-evoked, cognition and behavior. However, the spatiotemporal organization properties and principles of this intrinsic activity have only been partially elucidated because of previous poor resolution of experimental data and limited analysis methods. Here we investigated continuous wave patterns in the 0.5-4 Hz (delta band) frequency range on data from high-spatiotemporal resolution optical voltage imaging of the upper cortical layers in anesthetized mice. Waves of population activities propagate in heterogeneous directions to coordinate neuronal activities between different brain regions. The complex wave patterns show characteristics of both stereotypy and variety. The location and type of wave patterns determine the dynamical evolution when different waves interact with each other. Local wave patterns of source, sink, or saddle emerge at preferred spatial locations. Specifically, "source" patterns are predominantly found in cortical regions with low multimodal hierarchy such as the primary somatosensory cortex. Our findings reveal principles that govern the spatiotemporal dynamics of spontaneous cortical activities and associate them with the structural architecture across the cortex. Intrinsic brain activities, as opposed to external stimulus-evoked responses, have increasingly gained attention, but it remains unclear how these intrinsic activities are spatiotemporally organized at the cortex-wide scale. By taking advantage of the high spatiotemporal resolution of optical voltage imaging, we identified five wave pattern types, and revealed the organization properties of different wave patterns and the dynamical mechanisms when they interact with each other. Moreover, we found a relationship between the emergence probability of local wave patterns and the multimodal structure hierarchy across cortical areas. Our findings reveal the principles of spatiotemporal wave dynamics of spontaneous activities and associate them with the underlying hierarchical architecture across the cortex.
皮层回路产生模式化活动，反映了内在的大脑动力学，为包括刺激诱发的认知和行为在内的一切活动奠定了基础。然而，由于先前实验数据分辨率差和分析方法有限，这种内在活动的时空组织特性和原则仅部分得到了解释。在这里，我们研究了麻醉小鼠上层皮层高时空分辨率光电压成像数据中 0.5-4 Hz（δ 频段）频率范围内的连续波模式。群体活动波以不均匀的方向传播，以协调不同脑区之间的神经元活动。复杂的波模式表现出刻板和多样的特征。波模式的位置和类型决定了不同波相互作用时的动力学演化。源、汇或鞍点的局部波模式出现在首选的空间位置。具体来说，“源”模式主要出现在低多模态层次结构的皮层区域，如初级体感皮层。我们的发现揭示了支配自发皮层活动时空动力学的原则，并将其与整个皮层的结构架构联系起来。与外部刺激诱发的反应相反，内在大脑活动越来越受到关注，但目前尚不清楚这些内在活动在皮层范围内是如何在时空上组织的。通过利用光电压成像的高时空分辨率，我们确定了五种波模式类型，并揭示了不同波模式的组织特性以及它们相互作用时的动力学机制。此外，我们发现局部波模式的出现概率与皮质区之间的多模态结构层次之间存在关系。我们的发现揭示了自发活动时空波动力学的原则，并将其与皮层下的分层结构联系起来。
