Koroleva V I, Davydov V I, Roshchina G Ya
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
Neurosci Behav Physiol. 2009 Jan;39(1):87-97. doi: 10.1007/s11055-008-9096-0. Epub 2008 Dec 17.
Reflection of cortical waves of spreading depression in changes in high-frequency gamma activity was shown to improve significantly in conditions of bipolar recording of brain electrical activity. Intense suppression of the EEG gamma range (37-47 Hz) was seen in all cortical areas studied at the moment of onset of waves of spreading depression. The drop in the power of EEG gamma activity had clear leading and trailing fronts, allowing the passage time of the wave to be evaluated in each cortical area, as well as the sequence of propagation. Waves of spreading depression were characterized by normal, i.e., sequential movements across the cortex, only in the first 3-4 experiments. When experiments were continued, there were changes in the latent period and distortions of the propagation sequence. In some cases, waves of spreading depression responded to standard injections of KCl by developing rapidly (0.5-2 min) over the whole of the dorsal surface of the neocortex. More frequently, the wave was delayed (to 6-9 min) was completely blocked in some areas of the cortex. Different types of mild convulsive activity could accompany both the rapid propagation of waves across the cortex and inhibition of wave development. In most cases, there were no electrophysiological signs of changes in neocortical excitability. However, alterations to the spatial characteristics of waves of spreading depression and the spontaneous appearance of repeated waves provided evidence of changes in the functional state of the brain. Overall, EEG spectral analysis in conscious rabbits allowed analysis of spreading depression both in cases of sequential propagation across the cortex and in cases of atypical modes of development of this phenomenon.
在脑电活动的双极记录条件下，发现高频γ活动变化中扩散性抑制的皮质波反射有显著改善。在扩散性抑制波开始时，在所研究的所有皮质区域均可见到脑电图γ频段（37 - 47赫兹）的强烈抑制。脑电图γ活动功率的下降有明显的前沿和后沿，这使得能够评估每个皮质区域波的通过时间以及传播顺序。扩散性抑制波仅在最初的3 - 4次实验中表现为正常，即在皮质上依次移动。当实验继续进行时，潜伏期会发生变化，传播顺序也会出现扭曲。在某些情况下，扩散性抑制波对标准氯化钾注射的反应是在新皮质的整个背表面迅速发展（0.5 - 2分钟）。更常见的是，波延迟（至6 - 9分钟），并且在皮质的某些区域完全受阻。不同类型的轻度惊厥活动可能伴随波在皮质上的快速传播以及波发展的抑制。在大多数情况下，没有新皮质兴奋性变化的电生理迹象。然而，扩散性抑制波的空间特征改变以及重复波的自发出现提供了大脑功能状态变化的证据。总体而言，清醒兔的脑电图频谱分析能够对扩散性抑制在跨皮质顺序传播以及该现象非典型发展模式的情况下进行分析。
