Department of Clinical Neurophysiology, MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, 7500 AE Enschede, The Netherlands.
Neuroimage. 2012 May 1;60(4):2323-34. doi: 10.1016/j.neuroimage.2012.02.042. Epub 2012 Feb 28.
During the maintenance period of propofol-induced general anesthesia, specific changes in spontaneous EEG rhythms can be observed. These comprise increased delta and theta power and the emergence of alpha oscillations over frontal regions. In this study we use a meanfield model of the thalamo-cortical system to reproduce these changes and to elucidate the underlying mechanisms. The model is able to reproduce the most dominant changes in the EEG and suggests that they are caused by the amplification of resonances within the thalamo-cortical system. Specifically, while observed increases in delta and alpha power are reflections of amplified resonances in the respective frequency bands, increases in theta power are caused indirectly by spectral power leakage from delta and alpha bands. The model suggests that these changes are brought about through increased inhibition within local cortical interneuron circuits. These results are encouraging and motivate more extensive use of neural meanfield models in elucidating the physiological mechanisms underlying the effects of pharmacological agents on macroscopic brain dynamics.
在丙泊酚诱导的全身麻醉维持期间，可以观察到自发脑电图节律的特定变化。这些变化包括 delta 和 theta 功率增加，以及额叶区域出现 alpha 振荡。在这项研究中，我们使用丘脑-皮层系统的平均场模型来再现这些变化，并阐明潜在的机制。该模型能够再现脑电图中最主要的变化，并表明这些变化是由丘脑-皮层系统内共振的放大引起的。具体来说，虽然观察到的 delta 和 alpha 功率增加反映了相应频带中放大的共振，但 theta 功率的增加是由 delta 和 alpha 带的光谱功率泄漏间接引起的。该模型表明，这些变化是通过局部皮质中间神经元回路中抑制作用的增加引起的。这些结果令人鼓舞，并促使更广泛地使用神经平均场模型来阐明药理学药物对宏观脑动力学影响的生理机制。
