Zoppi M, Voegelin M R, Signorini M, Zamponi A
Department of Rheumatology, University of Florence, Italy.
Acta Physiol Scand. 1991 Dec;143(4):439-43. doi: 10.1111/j.1748-1716.1991.tb09256.x.
The purpose of this research is to evaluate the changes of cutaneous pain threshold induced by vibratory stimuli applied to the skin. The pain threshold was tested by means of electrical stimuli using the method of limits. Both vibratory stimuli (conditioning stimuli) and electrical stimuli (test stimuli) were driven by a computer. The experiments were carried out on the dorsal surface of the second phalanx of the index finger in the dominant hand of 34 healthy subjects (18 males and 16 females). The conditioning stimuli were sinusoidal waves (250 microm peak to peak) at a rate of 30 and 300 Hz. During the experiment (6 min of vibration and 9 min after) the cutaneous temperature of the stimulated area was recorded. Both vibratory rates induced significant increases of the pain threshold but the 30 Hz vibrations were the more effective. After stimulation the pain threshold lowered to a steady value which was higher than before the start of vibrations. Such threshold changes showed no correlation throughout the experiment with changes in skin temperature. We therefore advance the hypothesis that the main factors which modulate the pain threshold are neuronal connections between tactile and pain pathways.
本研究的目的是评估施加于皮肤的振动刺激所引起的皮肤痛阈变化。采用极限法通过电刺激来测试痛阈。振动刺激（条件刺激）和电刺激（测试刺激）均由计算机驱动。实验在34名健康受试者（18名男性和16名女性）优势手食指第二指节的背侧进行。条件刺激为频率30和300Hz的正弦波（峰峰值250微米）。在实验过程中（振动6分钟及之后9分钟）记录受刺激区域的皮肤温度。两种振动频率均引起痛阈显著升高，但30Hz的振动更有效。刺激后痛阈降至一个稳定值，该值高于振动开始前的值。在整个实验过程中，这种阈值变化与皮肤温度变化无相关性。因此，我们提出假说，即调节痛阈的主要因素是触觉和痛觉通路之间的神经元连接。
