Ploner Markus, Gross Joachim, Timmermann Lars, Pollok Bettina, Schnitzler Alfons
Department of Neurology, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany.
Neuroimage. 2006 Sep;32(3):1231-6. doi: 10.1016/j.neuroimage.2006.06.004. Epub 2006 Jul 18.
The neuronal activity of the resting human brain is dominated by spontaneous oscillations in primary sensory and motor areas. These oscillations are thought to reflect the excitability of sensory and motor systems that can be modulated according to the actual behavioral demands. However, so far, evidence for an association between oscillatory activity and excitability has been inconsistent. Here, we used magnetoencephalography to reinvestigate the relationship between oscillatory activity and excitability in the somatosensory system on a single trial basis. Brief painful stimuli were applied to relate pain-induced suppressions of oscillatory activity to pain-induced increases in excitability. The analysis reveals a significant negative correlation between sensorimotor oscillatory activity, particularly in the alpha-band, and excitability of somatosensory cortices. Oscillatory activity outside the somatosensory system did not correlate with somatosensory excitability. These findings demonstrate that modulations of sensorimotor oscillatory activity specifically reflect modulations in excitability of the somatosensory system and thus provide direct evidence for the basic tenet of an association between oscillatory activity and cortical excitability.
静息状态下人类大脑的神经元活动主要由初级感觉和运动区域的自发振荡主导。这些振荡被认为反映了感觉和运动系统的兴奋性，而这种兴奋性可根据实际行为需求进行调节。然而，到目前为止，振荡活动与兴奋性之间存在关联的证据并不一致。在此，我们使用脑磁图在单次试验的基础上重新研究体感系统中振荡活动与兴奋性之间的关系。施加短暂的疼痛刺激，将疼痛引起的振荡活动抑制与疼痛引起的兴奋性增加联系起来。分析揭示了感觉运动振荡活动，特别是α波段的振荡活动，与体感皮层的兴奋性之间存在显著的负相关。体感系统之外的振荡活动与体感兴奋性无关。这些发现表明，感觉运动振荡活动的调制具体反映了体感系统兴奋性的调制，从而为振荡活动与皮层兴奋性之间存在关联这一基本原理提供了直接证据。
