Influence of stimulation intensity on paired-pulse suppression of human median nerve somatosensory evoked potentials
Influence of stimulation intensity on paired-pulse suppression of human median nerve somatosensory evoked potentials
复制标题
刺激强度对人正中神经体感诱发电位配对脉冲抑制的影响
作者：
M. A. Gatica Tossi;Ann;H. Dinse
成对脉冲刺激，即连续施加两种刺激，是研究皮质兴奋性的有用工具。短刺激间隔后第二反应的抑制表征了成对脉冲行为。尽管成对脉冲抑制经常被研究为人类皮质兴奋性的标志，但人们对刺激强度对成对脉冲抑制的影响知之甚少。为了系统地探讨刺激强度对正中神经体感诱发电位 (MNSEP) 的成对脉冲抑制的影响，我们使用 10、30 和 100 ms 的刺激间隔，使用从感觉阈值到 1.2 倍运动阈值的刺激强度，记录了健康志愿者的单脉冲或成对脉冲 MNSEP。在各种体感诱发电位成分中，只有 N20-P25 成分表现出强度效应，其中较高的强度导致更强的配对脉冲抑制。然而，当仅考虑中间强度时，成对脉冲抑制不受影响或仅受到微弱影响。我们的数据表明，与单脉冲诱发的 MNSEP 相比，刺激强度对早期 MNSEP 的配对脉冲抑制只有微弱的影响。成对脉冲抑制被认为是由皮质内网络产生的抑制引起的。测试范围内缺乏强度依赖性可以被视为朝着创建针对刺激强度波动的不变性的一步。因此，与前馈处理相比，成对脉冲行为中明显的皮质内计算可能具有不同的特性。
Paired-pulse stimulation, the application of two stimuli in close succession, is a useful tool to investigate cortical excitability. Suppression of the second response after short interstimulus intervals characterizes paired-pulse behavior. Although paired-pulse suppression is often studied as a marker of cortical excitability in humans, little is known about the influence of stimulation intensity on paired-pulse suppression. To systematically explore the effect of stimulus intensity on paired-pulse suppression of median nerve somatosensory evoked potentials (MNSEPs), we recorded single-pulse or paired-pulse MNSEPs in healthy volunteers using stimulation intensities ranging from the sensory threshold to 1.2 times the motor threshold using interstimulus intervals of 10, 30, and 100 ms. Of the various somatosensory evoked potential components, only the N20-P25 component showed an effect of intensity, where higher intensities resulted in stronger paired-pulse suppression. However, when only intermediate intensities were considered, paired-pulse suppression was not or only weakly influenced. Our data suggest that stimulation intensity in contrast to single pulse-evoked MNSEPs has only a weak influence on the paired-pulse suppression of early MNSEPs. Paired-pulse suppression is believed to arise from inhibition generated by intracortical networks. The lack of intensity dependence within the range tested can be considered as a step toward creating invariance against fluctuations of stimulus intensity. Thus, intracortical computations as apparent in paired-pulse behavior might be characterized by different properties compared with feed-forward processing.
影响因子：
2.5
作者：
Hartings, JA;Simons, DJ
通讯作者：
Simons, DJ