Inui Koji, Tsuji Takeshi, Kakigi Ryusuke
Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji, Okazaki 444-8585, Japan.
Cereb Cortex. 2006 Mar;16(3):355-65. doi: 10.1093/cercor/bhi114. Epub 2005 May 18.
The mechanisms by which vibrotactile stimuli relieve pain are not well understood, especially in humans. We recorded cortical magnetic responses to paired noxious (intra-epidermal electrical stimulation, IES) and innocuous (transcutaneous electrical stimulation, TS) stimuli applied to the back at a conditioning-test interval (CTI) of -500 to 500 ms. Results showed that IES-induced responses were remarkably attenuated when TS was applied 20-60 ms later and 0-500 ms earlier than IES (CTI = -60 to 500 ms). Since the signals evoked by IES reached the spinal cord (CTI = -60 to -20 ms conditions) and the cortex (-60 and -40 ms condition) earlier than those evoked by TS, the present results indicate that cortical responses to noxious stimuli can be inhibited by innocuous tactile stimuli at the cortical level, with minimal contribution at the spinal level.
振动触觉刺激缓解疼痛的机制尚未完全明确，尤其是在人类中。我们记录了在-500至500毫秒的条件-测试间隔（CTI）下，对施加于背部的成对有害（表皮内电刺激，IES）和无害（经皮电刺激，TS）刺激的皮质磁反应。结果显示，当TS在IES之后20 - 60毫秒以及比IES早0 - 500毫秒施加时（CTI = -60至500毫秒），IES诱发的反应显著减弱。由于IES诱发的信号比TS诱发的信号更早到达脊髓（CTI = -60至-20毫秒条件）和皮质（-60和-40毫秒条件），目前的结果表明，在皮质水平，无害的触觉刺激可以抑制对有害刺激的皮质反应，而在脊髓水平的作用最小。
