NeuroImage
May 1, 2021
Pengmin Qin, Xuehai Wu, Changwei Wu et al.
51 citations
Consciousness depends on a network of brain regions that integrate sensory and motor information. Analyzing fMRI data from people in preserved (awake, fully conscious brain-injury survivors), reduced (N1-sleep, minimally conscious), and lost (N3-sleep, anesthesia, unresponsive wakefulness) states, plus a unique rapid-eye-movement (REM) sleep group, researchers identified key hubs whose degree centrality—a measure of network importance—dropped significantly when consciousness was reduced or absent. These hubs included the supplementary motor area, bilateral supramarginal gyrus, supragenual/dorsal anterior cingulate cortex, and left middle temporal gyrus. A higher-order sensorimotor circuit connecting these regions showed functional connectivity that correlated with consciousness levels across groups and remained active in REM sleep, suggesting this circuit supports consciousness and offers new targets for treating disorders of consciousness.
British journal of anaesthesia
March 1, 2024
Zhenhu Liang, Yu Chang, Xiaoge Liu et al.
10 citations
Information integration and brain network measures derived from EEG can distinguish conscious from unconscious states induced by three different anaesthetics. In 72 participants given propofol, dexmedetomidine, or ketamine until they lost responsiveness, permutation cross mutual information (PCMI) within frontal, parietal, and occipital regions decreased during unresponsiveness—for example, frontal within-area PCMI fell from 0.54 to 0.46. Alpha-band PCMI in the frontal region and gamma-band PCMI in posterior areas also dropped. Network analyses showed reduced clustering coefficients and nodal efficiency in frontal, parietal, and occipital areas, while normalized path length increased in delta, theta, and gamma bands, indicating impaired global integration. The three drugs produced similar changes, suggesting a common EEG signature of anaesthesia-induced unconsciousness.
Brain research bulletin
November 22, 2025
Yinying Sun, Bo Li, Yiting Wang et al.
A low dose of esketamine (2 mg/kg) significantly accelerated awakening from propofol anesthesia in adult C57BL/6J mice. In the prefrontal cortex, esketamine hastened the emergence of γ oscillations and triggered earlier activation of neuronal somata and dendrites in layer V, while delaying activation in layer II/III neurons. It also induced inter-layer phase desynchronization and a premature increase in acetylcholine and 5-hydroxytryptamine levels. The findings suggest that low-dose esketamine facilitates awakening by orchestrating a sequence of neural events in the prefrontal cortex, providing mechanistic insight into paradoxical emergence from anesthesia.