Coma Science Group, Cyclotron Research Centre and Neurology Department, University and University Hospital of Liège, Liège, Belgium.
PLoS One. 2013 Aug 19;8(8):e71370. doi: 10.1371/journal.pone.0071370. eCollection 2013.
Mechanisms of propofol-induced loss of consciousness remain poorly understood. Recent fMRI studies have shown decreases in functional connectivity during unconsciousness induced by this anesthetic agent. Functional connectivity does not provide information of directional changes in the dynamics observed during unconsciousness. The aim of the present study was to investigate, in healthy humans during an auditory task, the changes in effective connectivity resulting from propofol induced loss of consciousness. We used Dynamic Causal Modeling for fMRI (fMRI-DCM) to assess how causal connectivity is influenced by the anesthetic agent in the auditory system. Our results suggest that the dynamic observed in the auditory system during unconsciousness induced by propofol, can result in a mixture of two effects: a local inhibitory connectivity increase and a decrease in the effective connectivity in sensory cortices.
异丙酚诱导意识丧失的机制仍知之甚少。最近的 fMRI 研究表明，这种麻醉剂诱导的无意识状态下，功能连接性降低。功能连接性并不能提供在无意识状态下观察到的动力学的方向变化的信息。本研究旨在探讨在健康人类进行听觉任务时，异丙酚诱导意识丧失对有效连接的变化。我们使用功能磁共振成像的动态因果建模（fMRI-DCM）来评估麻醉剂在听觉系统中如何影响因果连接。我们的结果表明，异丙酚诱导的无意识状态下听觉系统中观察到的动态，可能导致两种效应的混合：局部抑制连接性增加和感觉皮层中有效连接性降低。
