Complexity Science Group, Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
Department of Psychiatry, University of Calgary, Calgary, AB, T2N 1N4, Canada.
Nat Commun. 2024 Aug 15;15(1):7025. doi: 10.1038/s41467-024-51399-2.
Scale-free statistics of coordinated neuronal activity, suggesting a universal operating mechanism across spatio-temporal scales, have been proposed as a necessary condition of healthy resting-state brain activity. Recent studies have focused on anesthetic agents to induce distinct neural states in which consciousness is altered to understand the importance of critical dynamics. However, variation in experimental techniques, species, and anesthetics, have made comparisons across studies difficult. Here we conduct a survey of several common anesthetics (isoflurane, pentobarbital, ketamine) at multiple dosages, using calcium wide-field optical imaging of the mouse cortex. We show that while low-dose anesthesia largely preserves scale-free statistics, surgical plane anesthesia induces multiple dynamical modes, most of which do not maintain critical avalanche dynamics. Our findings indicate multiple pathways away from default critical dynamics associated with quiet wakefulness, not only reflecting differences between these common anesthetics but also showing significant variations in individual responses. This is suggestive of a non-trivial relationship between criticality and the underlying state of the subject.
无标度统计的协调神经元活动，表明在时空尺度上存在普遍的运作机制，被认为是健康静息状态大脑活动的必要条件。最近的研究集中在麻醉剂上，以诱导不同的神经状态，改变意识以了解关键动力学的重要性。然而，由于实验技术、物种和麻醉剂的差异，使得跨研究的比较变得困难。在这里，我们使用小鼠皮层的钙宽场光学成像，对几种常见的麻醉剂（异氟烷、戊巴比妥、氯胺酮）在多个剂量下进行了调查。我们表明，虽然低剂量麻醉剂在很大程度上保留了无标度统计，但手术平面麻醉会诱导多种动力学模式，其中大多数模式都不能保持关键的雪崩动力学。我们的研究结果表明，与安静觉醒相关的默认关键动力学存在多种途径，这不仅反映了这些常见麻醉剂之间的差异，还显示了个体反应的显著变化。这表明关键值与受试者的潜在状态之间存在着复杂的关系。
