Vyazovskiy V V, Tobler I, Winsky-Sommerer R
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
Neuroscience. 2007 Jul 13;147(3):833-41. doi: 10.1016/j.neuroscience.2007.05.003. Epub 2007 Jun 13.
We tested the hypothesis that the effects of GABAergic agonists on behavior and the electroencephalogram (EEG) result from an increased regional synchronization in cortical circuits. The relationship between regional EEG topography, EEG synchronization and alteration of behavior was investigated by administering male C57BL/6 mice (n=7) a high, 3 mg/kg i.p. dose of muscimol, a selective GABA(A) agonist. Parietal and frontal cortical EEG, electromyogram, infrared and running wheel activity were recorded for 3 h before and 9 h after injection. Muscimol consistently elicited biphasic behavioral changes. Initially, it induced a catalepsy-like state lasting 96.0+/-12.4 min. This state was followed by a hyperactivity period of 49.7+/-5.4 min, during which the mice engaged in vigorous wheel running. During catalepsy, the EEG exhibited high amplitude waves which showed a consistent phase relationship between the frontal and parietal derivation. Moreover, the typical regional differences between the EEG spectra of the two derivations were abolished, and a redistribution of EEG power toward lower frequencies (<3 Hz) occurred in both derivations. In contrast, during hyperactivity the parietal EEG was dominated by theta-activity (7-9 Hz), which is typical for running behavior, while high amplitude slow waves, resembling the normal non-rapid eye movement sleep EEG pattern, predominated in the frontal EEG. The data indicate that the GABAergic system is involved in the regulation of cortical synchronization of neuronal activity and suggest a link between regional EEG synchronization and behavioral states.
我们验证了这样一个假设，即γ-氨基丁酸能（GABAergic）激动剂对行为和脑电图（EEG）的影响源于皮质回路中区域同步性的增强。通过给雄性C57BL/6小鼠（n = 7）腹腔注射3 mg/kg的高剂量蝇蕈醇（一种选择性GABA(A)激动剂），研究了区域脑电图地形图、EEG同步性与行为改变之间的关系。在注射前3小时和注射后9小时记录顶叶和额叶皮质脑电图、肌电图、红外活动和转轮活动。蝇蕈醇始终引起双相行为变化。最初，它诱导出一种持续96.0±12.4分钟的类僵住状态。随后是一个49.7±5.4分钟的多动期，在此期间小鼠进行剧烈的转轮奔跑。在僵住期间，EEG表现出高振幅波，额叶和顶叶导联之间呈现一致的相位关系。此外，两个导联EEG频谱的典型区域差异消失，两个导联的EEG功率都向低频（<3 Hz）重新分布。相反，在多动期间，顶叶EEG以θ活动（7 - 9 Hz）为主，这是奔跑行为的典型特征，而额叶EEG中类似于正常非快速眼动睡眠EEG模式的高振幅慢波占主导。数据表明，GABA能系统参与了神经元活动的皮质同步调节，并提示区域EEG同步与行为状态之间存在联系。
