Brain Connectivity Dissociates Responsiveness from Drug Exposure during Propofol-Induced Transitions of Consciousness.
Brain Connectivity Dissociates Responsiveness from Drug Exposure during Propofol-Induced Transitions of Consciousness.
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DOI：
10.1371/journal.pcbi.1004669
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发表时间：
2016-01
影响因子：
4.3
通讯作者：
Bekinschtein TA
中科院分区：
文献类型：
--
作者：
Chennu S;O'Connor S;Adapa R;Menon DK;Bekinschtein TA
对神经科学来说，准确测量意识的神经关联是一个巨大的挑战。尽管在理论上取得了进步，但由于麻醉易感性的显著个体差异，开发可靠的大脑测量方法来追踪镇静期间可报告的意识丧失受到了阻碍。我们使用高密度脑电图来描述异丙酚镇静期间脑网络的变化，从而解决了这一挑战。在镇静之前、期间和之后的频谱连接网络评估与行为反应性和血液中药物浓度的测量相结合。引人注目的是，我们发现，基线α带网络较弱的参与者在镇静期间更有可能变得无反应，尽管血液中的药物水平相似。相反，慢振荡和α振荡之间的相位振幅耦合与血液中的药物浓度相关。我们的发现突出了预测异丙酚易感性个体差异和追踪药物暴露的新标记。这些进展可以为麻醉期间准确的药物滴定和大脑状态监测提供信息。尽管对大脑网络如何产生意识的科学理解近年来取得了快速进展，但由于个体之间这个渐进过程的相当大的差异，将这些知识应用于准确跟踪全身麻醉期间向无意识的转变已被证明是困难的。使用高密度脑电图，我们研究了健康成人使用异丙酚镇静后这些网络的变化。通过测量他们的行为反应和血液中镇静剂的含量，我们发现了一个惊人的模式：在服用镇静剂之前，他们的大脑网络的强度预测了为什么有些参与者失去意识，而另一些人没有，尽管血液中的药物含量相似。通过揭示这种变异性的潜在特征，我们的发现可以在麻醉期间进行准确的大脑监测，并最大限度地减少术中意识。
Accurately measuring the neural correlates of consciousness is a grand challenge for neuroscience. Despite theoretical advances, developing reliable brain measures to track the loss of reportable consciousness during sedation is hampered by significant individual variability in susceptibility to anaesthetics. We addressed this challenge using high-density electroencephalography to characterise changes in brain networks during propofol sedation. Assessments of spectral connectivity networks before, during and after sedation were combined with measurements of behavioural responsiveness and drug concentrations in blood. Strikingly, we found that participants who had weaker alpha band networks at baseline were more likely to become unresponsive during sedation, despite registering similar levels of drug in blood. In contrast, phase-amplitude coupling between slow and alpha oscillations correlated with drug concentrations in blood. Our findings highlight novel markers that prognosticate individual differences in susceptibility to propofol and track drug exposure. These advances could inform accurate drug titration and brain state monitoring during anaesthesia. Though scientific understanding of how brain networks generate consciousness has seen rapid advances in recent years, application of this knowledge to accurately track transitions to unconsciousness during general anaesthesia has proven difficult due to considerable variability in this gradual process across individuals. Using high-density electroencephalography, we studied changes in these networks as healthy adults were sedated using propofol. By measuring their behavioural responsiveness and amount of sedative in their blood, we found a striking pattern: the strength of their brain networks before sedation predicted why some participants lost consciousness while others did not, despite registering similar blood levels of drug. By uncovering underlying signatures of this variability, our findings could enable accurate brain monitoring during anaesthesia and minimise intra-operative awareness.