Natural Frequencies of Human Corticothalamic Circuits
Natural Frequencies of Human Corticothalamic Circuits
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DOI：
10.1523/jneurosci.0445-09.2009
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发表时间：
2009-06-17
影响因子：
5.3
通讯作者：
Massimini, Marcello
中科院分区：
文献类型：
--
作者：
Rosanova, Mario;Casali, Adenauer;Massimini, Marcello
一个系统的频率调谐可以直接通过扰动它和观察随后的振荡率来确定，即所谓的自然频率。例如，在物理学、地质学中，以及在为乐器调音时，都使用这种方法。在本研究中，我们采用经颅磁刺激（TMS）直接扰动一组选定的皮质丘脑模块（布罗德曼区19，7和6）和高密度脑电图，以测量其自然频率。经颅磁刺激在枕叶皮层中持续诱发显性α波段振荡（8-12 Hz），在顶叶皮层中诱发显性β波段振荡（13-20 Hz），在额叶皮层中诱发显性快速β/γ波段振荡（21-50 Hz）。当TMS通过大脑连接间接参与时，以及当以不同强度刺激时，每个皮层区域都倾向于保持自己的自然频率，这表明观察到的振荡反映了局部生理机制。这些发现是可重复的个人和代表的第一个直接表征的粗糙的电生理特性的三个关联领域的人类大脑皮层。最重要的是，他们指出，在健康的受试者，每个皮质丘脑模块通常被调谐到振荡的特征率。自然频率几乎可以在大脑皮层的任何区域直接测量，并且可以代表一种直接和灵活的方式来探测患者床边的人类丘脑皮层回路的状态。
The frequency tuning of a system can be directly determined by perturbing it and by observing the rate of the ensuing oscillations, the so called natural frequency. This approach is used, for example, in physics, in geology, and also when one tunes a musical instrument. In the present study, we employ transcranial magnetic stimulation (TMS) to directly perturb a set of selected corticothalamic modules (Brodmann areas 19, 7, and 6) and high-density electroencephalogram to measure their natural frequency. TMS consistently evoked dominant alpha-band oscillations (8-12 Hz) in the occipital cortex, beta-band oscillations (13-20 Hz) in the parietal cortex, and fast beta/gamma-band oscillations (21-50 Hz) in the frontal cortex. Each cortical area tended to preserve its own natural frequency also when indirectly engaged by TMS through brain connections and when stimulated at different intensities, indicating that the observed oscillations reflect local physiological mechanisms. These findings were reproducible across individuals and represent the first direct characterization of the coarse electrophysiological properties of three associative areas of the human cerebral cortex. Most importantly, they indicate that, in healthy subjects, each corticothalamic module is normally tuned to oscillate at a characteristic rate. The natural frequency can be directly measured in virtually any area of the cerebral cortex and may represent a straightforward and flexible way to probe the state of human thalamocortical circuits at the patient's bedside.