Liang Zhenhu, Fan Luxin, Zhang Bin, Shu Wei, Li Duan, Li Xiaoli, Yu Tao
Key Laboratory of Intelligent Control and Neural Information Processing of the Ministry of Education of China, Yanshan University, Qinhuangdao 066004, Hebei, China; Key Laboratory of Intelligent Rehabilitation and Neuromodulation of Hebei Province, Yanshan University, Qinhuangdao 066004, China.
Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
Neuroimage. 2025 May 1;311:121193. doi: 10.1016/j.neuroimage.2025.121193. Epub 2025 Apr 9.
Existing studies have indicated neural activity across diverse temporal and spatial scales. However, the alterations in complexity, functional connectivity, and directional connectivity within the thalamocortical and corticocortical systems across various scales during propofol-induced unconsciousness remain uncertain. We analyzed the stereo-electroencephalography (SEEG) from wakefulness to unconsciousness among the brain regions of the prefrontal cortex, temporal lobe, and anterior nucleus of the thalamus. The complexity (examined by permutation entropy (PE)), functional connectivity (permutation mutual information (PMI)), and directional connectivity (symbolic conditional mutual information (SCMI) and directionality index (DI)) were calculated across various scales. In the lower-band frequency (0.1-45 Hz) SEEG, after the loss of consciousness, PE significantly decreased (p < 0.001) in all regions and scales, except for the thalamus, which remained relatively unchanged at large scales (τ=32 ms). Following the loss of consciousness, inter-regional PMI either significantly increased or remained stable across different scales (τ=4 ms to 32 ms). During the unconscious state, SCMI between brain regions exhibited inconsistent changes across scales. In the late unconscious stage, the inter-regional DI across all scales indicated a shift from a balanced state of information flow between brain regions to a pattern where the prefrontal cortex and thalamus drive the temporal lobe. Our findings demonstrate that propofol-induced unconsciousness is associated with reduced cortical complexity, diverse functional connectivity, and a disrupted balance of information integration among thalamocortical and cortico-cortical systems. This study enhances the theoretical understanding of anesthetic-induced loss of consciousness by elucidating the scale- and region-specific effects of propofol on thalamocortical and cortico-cortical systems.
现有研究表明了不同时间和空间尺度上的神经活动。然而，在丙泊酚诱导的意识丧失过程中，丘脑皮质和皮质皮质系统在各个尺度上的复杂性、功能连接性和方向连接性的变化仍不明确。我们分析了前额叶皮质、颞叶和丘脑前核等脑区从清醒到意识丧失期间的立体脑电图（SEEG）。计算了各个尺度上的复杂性（通过排列熵（PE）检验）、功能连接性（排列互信息（PMI））和方向连接性（符号条件互信息（SCMI）和方向性指数（DI））。在低频带（0.1 - 45 Hz）的SEEG中，意识丧失后，除丘脑在大尺度（τ = 32 ms）下相对保持不变外，所有区域和尺度的PE均显著降低（p < 0.001）。意识丧失后，不同尺度（τ = 4 ms至32 ms）的区域间PMI要么显著增加，要么保持稳定。在无意识状态下，脑区之间的SCMI在不同尺度上表现出不一致的变化。在无意识后期，所有尺度上的区域间DI表明，信息流从脑区之间的平衡状态转变为前额叶皮质和丘脑驱动颞叶的模式。我们的研究结果表明，丙泊酚诱导的意识丧失与皮质复杂性降低、功能连接性多样以及丘脑皮质和皮质 - 皮质系统之间信息整合平衡被破坏有关。本研究通过阐明丙泊酚对丘脑皮质和皮质 - 皮质系统的尺度和区域特异性影响，增强了对麻醉诱导意识丧失的理论理解。
