Huang Zirui, Mashour George A, Hudetz Anthony G
Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
bioRxiv. 2024 Jan 24:2024.01.23.576934. doi: 10.1101/2024.01.23.576934.
Research into the role of thalamocortical circuits in anesthesia-induced unconsciousness is difficult due to anatomical and functional complexity. Prior neuroimaging studies have examined either the thalamus as a whole or focused on specific subregions, overlooking the distinct neuronal subtypes like core and matrix cells. We conducted a study of heathy volunteers and functional magnetic resonance imaging during conscious baseline, deep sedation, and recovery. We advanced the functional gradient mapping technique to delineate the functional geometry of thalamocortical circuits, within a framework of the unimodal-transmodal functional axis of the cortex. We observed a significant shift in this geometry during unconsciousness, marked by the dominance of unimodal over transmodal geometry. This alteration was closely linked to the spatial variations in the density of matrix cells within the thalamus. This research bridges cellular and systems-level understanding, highlighting the crucial role of thalamic core-matrix functional architecture in understanding the neural mechanisms of states of consciousness.
由于解剖结构和功能的复杂性，研究丘脑皮质回路在麻醉诱导的意识丧失中的作用具有一定难度。先前的神经影像学研究要么将丘脑作为一个整体进行研究，要么聚焦于特定的亚区域，而忽略了像核心细胞和基质细胞这样不同的神经元亚型。我们对健康志愿者进行了一项研究，并在清醒基线、深度镇静和恢复过程中进行了功能磁共振成像。我们改进了功能梯度映射技术，以在皮质单峰-跨模态功能轴的框架内描绘丘脑皮质回路的功能几何结构。我们观察到在无意识状态下这种几何结构发生了显著变化，其特征是单峰几何结构比跨模态几何结构占主导地位。这种改变与丘脑内基质细胞密度的空间变化密切相关。这项研究将细胞层面和系统层面的理解联系起来，突出了丘脑核心-基质功能结构在理解意识状态神经机制中的关键作用。
