A central mechanism enhances pain perception of noxious thermal stimulus changes.
A central mechanism enhances pain perception of noxious thermal stimulus changes.
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一个中心机制增强了有害热刺激变化的疼痛感知。
DOI：
10.1038/s41598-017-04009-9
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发表时间：
2017
影响因子：
4.6
通讯作者：
Apkarian,AV
中科院分区：
文献类型：
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作者：
Petre,B;Tetreault,P;Mathur,VA;Schurgin,MW;Chiao,JY;Huang,L;Apkarian,AV
疼痛感知暂时夸大突然的热刺激变化揭示了伤害性时间对比度增强（TCE）的机制。虽然机制是未知的，但具有感知反馈的非线性模型准确地模拟了这种现象。在这里，我们测试，如果在中枢神经系统的机制是热TCE。我们的模型成功地预测了一个最佳的刺激，包括一个瞬时的温度偏移（升压/降压），最大的TCE，导致精神病理学证实的疼痛反应的大幅度下降（“偏移镇痛”;平均镇痛：85%，n = 20名受试者）。接下来，使用两个热电偶递送该刺激，一个递送较长持续时间的基线温度脉冲，另一个叠加较短的较高温度脉冲。这两种刺激同时施加在同一手臂或相反的手臂上。跨多个外周感受野的空间分离确保复合刺激时程首先在中枢神经系统中重构。同侧刺激停止后的高温热电极，但停止前的低温刺激性能的TCE进行了观察，无论是个人受试者和组的平均反应。这表明中枢整合机制足以引起疼痛的热TCE，这是将瞬时传入伤害性信号转化为稳定疼痛感知的重要步骤。
Pain perception temporarily exaggerates abrupt thermal stimulus changes revealing a mechanism for nociceptive temporal contrast enhancement (TCE). Although the mechanism is unknown, a non-linear model with perceptual feedback accurately simulates the phenomenon. Here we test if a mechanism in the central nervous system underlies thermal TCE. Our model successfully predicted an optimal stimulus, incorporating a transient temperature offset (step-up/step-down), with maximal TCE, resulting in psychophysically verified large decrements in pain response (“offset-analgesia”; mean analgesia: 85%,n= 20 subjects). Next, this stimulus was delivered using two thermodes, one delivering the longer duration baseline temperature pulse and the other superimposing a short higher temperature pulse. The two stimuli were applied simultaneously either near or far on the same arm, or on opposite arms. Spatial separation across multiple peripheral receptive fields ensures the composite stimulus timecourse is first reconstituted in the central nervous system. Following ipsilateral stimulus cessation on the high temperature thermode, but before cessation of the low temperature stimulus properties of TCE were observed both for individual subjects and in group-mean responses. This demonstrates a central integration mechanism is sufficient to evoke painful thermal TCE, an essential step in transforming transient afferent nociceptive signals into a stable pain perception.