Vision of the Body Modulates Somatosensory Intracortical Inhibition
Vision of the Body Modulates Somatosensory Intracortical Inhibition
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DOI：
10.1093/cercor/bhq267
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发表时间：
2011-09-01
期刊：
影响因子：
3.7
通讯作者：
Haggard, Patrick
中科院分区：
文献类型：
--
作者：
Cardini, Flavia;Longo, Matthew R.;Haggard, Patrick
同时电刺激相邻手指所诱发的体感诱发电位(SEPs)的幅度一般小于单独刺激每个手指所诱发的电位之和。这种低相加性表明相邻皮肤区域的表达之间存在抑制，并可能反映了躯体感觉皮层中间神经元的侧向抑制过程。鉴于简单地观察身体可以提高触觉敏锐度，并且触觉敏锐度依赖于皮质侧向抑制，我们研究了观察身体如何调节来自相邻手指的同时传入截击之间的抑制相互作用。我们分别或同时记录了电刺激右手食指和中指时诱发的SEP，同时受试者看到自己的手或物体。在一连串的电刺激之间，参与者辨别出施加在两个手指上的触觉栅格的方向。与之前的发现一致，观看手部增强了触觉敏锐度。此外，由于同时电刺激两个手指，观察手部增加了对P50电位的抑制。此外，受试者触觉表现的视觉增强与抑制的视觉调制相关。这些结果表明，视觉通过调节躯体感觉皮层中抑制性神经元间回路的活动来增强躯体感觉。
The magnitude of somatosensory evoked potentials (SEPs) elicited by simultaneous electrical stimulation of adjacent digits is generally less than the sum of potentials evoked by stimulation of each digit individually. This under-additivity suggests suppression between representations of adjacent skin regions and may reflect a process of lateral inhibition by interneurons in somatosensory cortex. Given that simply viewing the body enhances tactile acuity and that tactile acuity depends on cortical lateral inhibition, we investigated how viewing the body modulates suppressive interactions between simultaneous afferent volleys from adjacent fingers. We recorded SEPs evoked by electrical stimulation of the right index and middle fingers, either individually or simultaneously, while participants viewed either their own hand or an object. In between trains of electrical stimuli, participants discriminated the orientation of tactile gratings applied to either finger. Consistent with previous findings, viewing the hand enhanced tactile acuity. Furthermore, viewing the hand increased the suppression of the P50 potential due to simultaneous electrical stimulation of both fingers. Moreover, the visual enhancement of tactile performance correlated across participants with the visual modulation of suppression. These results demonstrate that vision enhances somatosensation by modulating activity of inhibitory interneuronal circuits in the somatosensory cortex.