LTP-like changes induced by paired associative stimulation of the primary somatosensory cortex in humans: source analysis and associated changes in behaviour
LTP-like changes induced by paired associative stimulation of the primary somatosensory cortex in humans: source analysis and associated changes in behaviour
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DOI：
10.1111/j.1460-9568.2007.05531.x
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发表时间：
2007-05-01
影响因子：
3.4
通讯作者：
Classen, Joseph
中科院分区：
文献类型：
--
作者：
Litvak, Vladimir;Zeller, Daniel;Classen, Joseph
配对联合刺激（PAS），结合重复周围神经刺激与经颅磁刺激（TMS），可能通过长时程增强样机制诱导体感皮层（S1）的神经可塑性变化。我们使用多通道正中神经体感诱发电位（MN-SSEP）记录和两点触觉辨别测试来检查这些变化的位置和行为意义。当TMS施加到S1近同步的传入信号包含机械感受性信息，MN-SSEP的变化（显着在21-31毫秒）可以解释位于布罗德曼区3b的切向源的变化，其时序和极性表明修改上皮层。PAS诱导的MN-SSEP在28和32 ms之间的变化与触觉辨别的变化呈线性相关。相反，当近同步传入信号主要包含本体感受信息时，PAS诱导的MN-SSEP变化（20-29 ms）向内侧移动，触觉表现保持稳定。随着近同步机械感受性刺激的两个相互作用的信号的时间的细微差异往往会影响触觉性能变化的方向。采用与传入脉冲异步输送的TMS进行的PAS不会改变MN-SSEPs。机械感受性传入信号与TMS诱发的活动的Hebbian相互作用可能会改变Brodmann区3b皮层浅层的突触功效，并与时间依赖性和定性一致的行为变化相关。
Paired associative stimulation (PAS), which combines repetitive peripheral nerve stimulation with transcranial magnetic stimulation (TMS), may induce neuroplastic changes in somatosensory cortex (S1), possibly by long-term potentiation-like mechanisms. We used multichannel median nerve somatosensory evoked potential (MN-SSEP) recordings and two-point tactile discrimination testing to examine the location and behavioural significance of these changes. When TMS was applied to S1 near-synchronously to an afferent signal containing mechanoreceptive information, MN-SSEP changes (significant at 21-31 ms) could be explained by a change in a tangential source located in Brodmann area 3b, with their timing and polarity suggesting modification of upper cortical layers. PAS-induced MN-SSEP changes between 28 and 32 ms were linearly correlated with changes in tactile discrimination. Conversely, when the near-synchronous afferent signal contained predominantly proprioceptive information, PAS-induced MN-SSEP changes (20-29 ms) were shifted medially, and tactile performance remained stable. With near-synchronous mechanoreceptive stimulation subtle differences in the timing of the two interacting signals tended to influence the direction of tactile performance changes. PAS performed with TMS delivered asynchronously to the afferent pulse did not change MN-SSEPs. Hebbian interaction of mechanoreceptive afferent signals with TMS-evoked activity may modify synaptic efficacy in superficial cortical layers of Brodmann area 3b and is associated with timing-dependent and qualitatively congruent behavioural changes.