标题： 猴脑皮层功能连接在丙泊酚诱导麻醉开始时的动力学变化 显示英文标题

标题： Macaque's Cortical Functional Connectivity Dynamics at the Onset of Propofol-Induced Anesthesia

摘要： 丙泊酚在用于全身麻醉时，会引发振荡性动态脑状态，这些状态被认为与药物的药理作用有关。 尽管已经阐明了丙泊酚在分子水平的作用机制，但其对神经回路和整体皮层功能的影响，最终导致无意识的状态，仍然不清楚。 为了确定可能的机制，需要描述麻醉受试者中专门皮层区域之间建立的功能连接的空间-时间模式。 在此背景下，本研究涉及对猴类在丙泊酚麻醉诱导下密集的硬膜下ECoG电极阵列记录数据的分析。 使用格兰杰因果关系方法，在五个生理频率带中依次推断功能连接相互作用，每隔五秒在整个实验过程中进行推断。 获得的时间解析网络使我们能够观察麻醉诱导的展开过程，并比较不同实验条件下获得的网络。 在给予丙泊酚约一分钟之后，功能连接开始增加4-5分钟，然后减少直到达到意识丧失（LOC）。 在转变过程中，也显示了从枕叶和颞叶区域向额叶和顶叶区域的主要格兰杰因果关系流动。 在全身麻醉期间，枕叶的局部连接增加，枕叶和颞叶之间的相互作用也增加。 相反，额叶和顶叶向颞叶和枕叶的功能连接主要受到损害。 这项研究是最早描述意识丧失（LOC）前过渡状态下功能连接动力学的研究之一。 显示英文摘要

摘要： Propofol, when administered for general anesthesia, induces oscillatory dynamic brain states that are thought to underlie the drug's pharmacological effects. Despite the elucidation of propofol's mechanisms of action at the molecular level, its effects on neural circuits and overall cortical functioning, which eventually lead to unconsciousness, are still unclear. To identify possible mechanisms, the spatial-temporal patterns of functional connectivity established among specialized cortical areas in anesthetized subjects need to be described. Within this context, the present research involved the analysis of dense sub-dural ECoG electrode array recordings from macaques under propofol anesthetic induction. Granger causality methodology was used to infer functional connectivity interactions in five physiological frequency bands serially over time, every five seconds throughout the experiment. The time-resolved networks obtained permitted us to observe the unfolding of the anesthetic induction and compare the networks obtained under different experimental conditions. About one minute after administering propofol, functional connectivity started to increase for 4-5 minutes, then decreased until the LOC was achieved. A predominant Granger causality flow from the occipital and temporal areas towards the frontal and parietal regions was also evidenced during the transition. During general anesthesia, the local connectivity of the occipital lobe increased, as did the interactions between the occipital and temporal lobes. Conversely, the functional connectivity from the frontal and parietal lobes toward the temporal and occipital regions was mainly impaired. The research is one of the first studies to describe the dynamics of the functional connectivity during the transitional state that precedes the LOC.