Excitability changes induced in the human primary visual cortex by transcranial direct current stimulation: Direct electrophysiological evidence
Excitability changes induced in the human primary visual cortex by transcranial direct current stimulation: Direct electrophysiological evidence
复制标题
DOI：
10.1167/iovs.03-0688
复制
发表时间：
2004-02-01
影响因子：
4.4
通讯作者：
Paulus, W
中科院分区：
文献类型：
--
作者：
Antal, A;Kincses, TZ;Paulus, W
目的.经颅直流电刺激（tDCS）已被证明可以改变由经颅磁刺激（TMS）引起的光幻视的感知阈值。本研究旨在探讨tDCS应用于枕叶皮层时是否也能以极性特异性方式影响视觉诱发电位（VEP），该电位表征枕叶对视觉刺激的激活。为此，在初级视觉皮层的阳极或阴极tDCS的5、10或15分钟结束之前、之后立即和之后10、20和30分钟记录由正弦亮度光栅以开/关模式诱发的VEP。只有当低对比度的视觉刺激时，才能观察到显着的效果。阴极刺激降低，而阳极刺激增加的幅度的N70组件。如果刺激持续时间足够长（即，10 - 15分钟）。在15分钟tDCS结束后仅10分钟，阳极刺激的N70振幅增加是显著的。阴极刺激也倾向于影响P100分量的幅度，然而，刺激的效果是相反的。阴极刺激结束后，振幅立即增加。相反，阳极刺激不影响P100。tDCS对N70和P100的潜伏期无明显影响。tDCS似乎是一个合适的方法，诱导可逆的兴奋性变化的极性特定的方式，不仅在电机，而且在初级视觉皮层。诱导的后效的持续时间不仅取决于刺激持续时间，还取决于刺激极性。阴极刺激似乎更有效，与以前的报告运动皮层。
PURPOSE. Transcranial direct current stimulation (tDCS) has been shown to modify the perception threshold of phosphenes elicited by transcranial magnetic stimulation (TMS). The current study was undertaken to examine whether tDCS, when applied over the occipital cortex, is also able to affect visual-evoked potentials (VEPs), which characterize occipital activation in response to visual stimulation, in a polarity-specific way.METHOD. For this purpose, VEPs evoked by sinusoidal luminance grating in an on/off mode were recorded before, immediately after, and 10, 20, and 30 minutes after the end of 5, 10, or 15 minutes of anodal or cathodal tDCS of the primary visual cortex.RESULTS. Significant effects were observed only when low-contrast visual stimuli were applied. Cathodal stimulation decreased, whereas anodal stimulation increased the amplitude of the N70 component. The effect of cathodal stimulation was significant immediately after and 10 minutes after the end of stimulation, if the stimulation duration was sufficiently long (i.e., 10 - 15 minutes). An increase of N70 amplitude by anodal stimulation was significant only 10 minutes after the end of the 15 minutes tDCS. Cathodal stimulation tended also to affect the amplitude of the P100 component; however, the effect of stimulation was inverse. The amplitude increased immediately after the end of cathodal stimulation. In contrast, anodal stimulation did not affect the P100. The latencies of the N70 and the P100 were not affected by tDCS.CONCLUSIONS. tDCS appears to be a suitable method of inducing reversible excitability changes in a polarity-specific way, not only in the motor but also in the primary visual cortex. The duration of the induced aftereffects depends not only on stimulation duration but also on stimulation polarity. Cathodal stimulation seems to be more effective, in line with previous reports on the motor cortex.