题目：Spontaneous brain activity: cortex-wide complex wave and nonlinear interaction with sensory-evoked activity（自发性大脑活动：全皮层复杂波及与感觉诱发活动的非线性相互作用）
报告人：周昌松 教授（香港浸会大学）
地点：紫金港校区西区海纳苑8幢322室
时间：2023年4月3日（周一），下午15:00
摘要：In the living brain, electrical activity is always present, also in the absence of external stimuli. The organization of the spatiotemporal dynamics of cortical activity, how they change with brain states and how they affect the processing of sensory stimulation, are far from being well understood. In early studies aimed at understanding how perception and behavior emerges from neuronal activities, spontaneous, ongoing activity was treated like irrelevant noise. Here our interdisciplinary collaborative research combines real-time high spatiotemporal resolution optical voltage imaging experiments and computational analysis and modelling based on dynamical system theory to study the evolution of wave patterns in mice in anesthesia and transitioning from anesthesia to wakefulness and awake mice. We find that, as the brain transitions into wakefulness, there is a reduction in hemisphere-scale voltage waves, and an increase in local wave events and complexity. A neural mass model recapitulates the essential cellular-level features and shows how the dynamical competition between global and local spatiotemporal patterns and long-range connections can explain the experimental observations. These mechanisms possibly endow the awake cortex with enhanced integrative processing capabilities. We further study how the spontaneous activity influences the response of the brain to whisker stimulation in awake mice. Clustering analysis reveals that the sensory-evoked activity propagates over the cortex via distinct pathways associated with distinct behavioral states. The pathway taken by each trial is independent of the level of primary sensory-evoked activation but is partially predictable by the spatiotemporal features of the preceding cortical spontaneous activity patterns. The sensory inputs reduce trial-to-trial variability in brain activity and alter temporal autocorrelation in spatial activity pattern evolutions, suggesting non-linear interactions between evoked activities and spontaneous activities. Further, evoked activities and spontaneous activities occupy different positions in the state space, suggesting that sensory inputs can intricately interact with the internal state to generate large-scale evoked activity patterns not frequented by spontaneous brain states.
Reference:
Yuqi Liang, Chenchen Song, Mianxin Liu, Pulin Gong, Changsong Zhou*, Thomas Knöpfel*, Cortex-wide dynamics of intrinsic electrical activities: propagating waves and their interactions. Journal of Neuroscience 41, 36635-36678 (2021).
Yuqi Liang, Junhao Liang, Chenchen Song†, Mianxin Liu, Thomas Knöpfel*, Pulin Gong* and Changsong Zhou*, Complexity of cortical wave patterns of the wake mouse cortex, Nature Communications 14:1434 (2023).
Mianxin Liu, Yuqi Liang, Chenchen Song, Thomas Knöpfel*, Changsong Zhou*, Cortex-wide spontaneous activity steers propagating sensory-evoked activity in awake mice, Cell Reports 41, 111740 (2022).
个人简介：
周昌松, 物理学博士，香港浸会大学物理系教授、系主任，浸会大学非线性研究中心主任,计算及理论研究所副所长,浸会大学核磁中心主任。1992年获南开大学物理学士, 1997年获南开大学物理博士，1997-2007年在新加坡、 香港、 德国等地从事访问研究, 是洪堡基金获得者。2007年加入香港浸会大学物理系，2011年获浸会大学“杰出青年研究者校长奖”，2021年获“杰出研究者校长奖”。周昌松博士致力于复杂系统动力学基础研究及其应用，特别是网络的复杂联结结构与体系的动态行为的关系和相互作用。近几年与国际国内系统和认知神经科学家合作，把这些理论进展应用到大脑的复杂联结结构和活动以及认知功能及障碍的分析和建模等方面研究中。周昌松博士对生物神经网络复杂结构、动力学及其高成本效益如何启发类脑智能具有浓厚的兴趣。在国际交叉学术刊物 Nature Communications, PNAS，PRL，Physics Reports，National Science Review, Cell Reports, Journal of Neuroscience,NeuroImage,PLoS Computational Biology等发表论文150余篇 (Google Scholar引用17000余次，H-因子为50)。任Scientific Reports 编委，PLoS One，Cognitive Neurodynamics学术编辑，及多种国际期刊常任审稿人。
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