Characteristics of temporal summation of second pain sensations elicited by brief contact of glabrous skin by a preheated thermode
Characteristics of temporal summation of second pain sensations elicited by brief contact of glabrous skin by a preheated thermode
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DOI：
10.1152/jn.1997.78.2.992
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发表时间：
1997-08-01
影响因子：
2.5
通讯作者：
Whitsel, BL
中科院分区：
文献类型：
--
作者：
Vierck, CJ;Cannon, RL;Whitsel, BL
使用新的热刺激方法研究了正常受试者感觉强度的时间总和。帕尔蒂埃热模式被加热，然后在一系列短暂(700毫秒)的接触中应用于两手无毛皮肤的不同位置。重复接触大鱼际或小鱼际隆起，以3 S的刺激间隔(ISIS)，逐渐增加每次接触后开始潜伏期的热感觉强度&2 S。这些延迟(晚)感觉的时间总和与体温在45-53摄氏度范围内成正比，从非疼痛水平(温暖)发展到疼痛感觉，10次接触后可被评为非常强烈。短潜伏期的痛感很少由这样的刺激引起，并且从未达到显著高于所呈现的序列和温度的痛阈值的水平。短暂接触产生的时间总和在速率和数量上都大于通过与皮肤持续接触的热模重复上升到相同温度所导致的感觉强度的增加。接触间隔的变化揭示了感觉强度对刺激间间隔的依赖，这类似于WINUP的生理学演示，即通过重复激活无髓鞘伤害性感受器，从脊髓神经元诱发出更高频率的棘波串活动。然而，在大于或等于0.33赫兹的重复频率下，观察到只有当以频率呈现时才产生晚期温暖感觉的温度的大量总和
Temporal summation of sensory intensity was investigated in normal subjects using novel methods of thermal stimulation. A Peltier thermode was heated and then applied in a series of brief (700 ms) contacts to different sites on the glabrous skin of either hand. Repetitive contacts on the thenar or hypothenar eminence, at interstimulus intervals (ISIs) of 3 s, progressively increased the perceived intensity of a thermal sensation that followed each contact at an onset latency >2 s. Temporal summation of these delayed (late) sensations was proportional to thermode temperature over a range of 45 - 53 degrees C, progressing from a nonpainful level (warmth) to painful sensations that could be rated as very strong after 10 contacts. Short-latency pain sensations rarely were evoked by such stimuli and never attained levels substantially above pain threshold for the sequences and temperatures presented. Temporal summation produced by brief contacts was greater in rate and amount than increases in sensory intensity resulting from repetitive ramping to the same temperature by a thermode in constant contact with the skin. Variation of the interval between contacts revealed a dependence of sensory intensity on interstimulus interval that is similar to physiological demonstrations of windup, where increasing frequencies of spike train activity are evoked from spinal neurons by repetitive activation of unmyelinated nociceptors. However, substantial summation at repetition rates of greater than or equal to 0.33 Hz was observed for temperatures that produced only late sensations of warmth when presented at frequencies