Professor Ti-Fei Yuan of Shanghai Jiao Tong University, in collaboration with Professors Tao Xu and Peng Xu of the University of Electronic Science and Technology of China, investigated the neural mechanism of consciousness. Their study, entitled “Neurophysiological Connectomic Signatures of Consciousness during Propofol-Induced General Anesthesia”, was published in Cell Reports Medicine on 29 January 2026. The study identified disrupted parietal-subcortical α-band functional connectivity as a critical neurophysiological signature of propofol-induced loss of consciousness.
Understanding the mechanisms of consciousness remains a major challenge in neuroscience. General anesthesia provides a valuable experimental tool for investigating reversible alterations in consciousness. Leveraging the clinical setting of propofol-induced general anesthesia, the research team conducted an in-depth analysis of the whole-brain electrophysiological functional connectome. The results showed that the propofol-induced unconsciousness was characterized by significantly increased low-frequency (δ and θ) network connectivity, accompanied by markedly reduced phase coupling in the α, β, and γ bands. This frequency-specific reorganization of functional networks may be closely associated with reversible transitions in consciousness. Furthermore, models based on α-band features outperformed those based on other frequency bands in classifying consciousness states. Specifically, α-band functional connectivity in parietal-subcortical, parietal-occipital, and parietal-temporal regions contributed most strongly to distinguishing conscious from unconscious states.
Transitions between conscious and unconscious states during general anesthesia occur within seconds. To capture these rapid dynamics, the study performed a sliding-window analysis with millisecond-level temporal resolution. The results showed that α-band phase-locking connectivity involving parietal regions, such as parietal-occipital, parietal-thalamic, parietal-cingulate, parietal-claustral, and parietal-temporal connections, tracked transitions in consciousness. These findings suggest that α band connectivity within parietal-related cortical-subcortical and posterior cortical networks may constitute a key neural mechanism underlying the dynamic loss of consciousness. The findings are highly consistent with the posterior ‘hot zone’ hypothesis, which emphasizes the critical integrative role of parietal and posterior cortical regions in supporting consciousness.
The findings were further validated in an independent cohort undergoing low-dose propofol sedation. The results confirmed that reduced parietal α connectivity is a robust neural marker of diminished consciousness, suggesting that this network may play a key role in anesthesia-induced loss of consciousness.
This study advances our understanding of anaesthesia-induced loss of consciousness. It identifies potential neural markers for assessing consciousness, with implications for individualized monitoring and regulation of anesthesia depth. The study was highlighted by Nature in a news article entitled “Still conscious? Brain marker signals when anaesthesia takes hold”.
Paper doi: https://doi.org/10.1016/j.xcrm.2025.102581
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