Nociceptive responses to high and low rates of noxious cutaneous heating are mediated by different nociceptors in the rat: Behavioral evidence
Nociceptive responses to high and low rates of noxious cutaneous heating are mediated by different nociceptors in the rat: Behavioral evidence
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DOI：
10.1016/s0304-3959(96)03176-4
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发表时间：
1996-11-01
期刊：
影响因子：
7.4
通讯作者：
Proudfit, HK
中科院分区：
文献类型：
--
作者：
Yeomans, DC;Pirec, V;Proudfit, HK
有几条证据表明，不同类别的伤害性感受性传入调节着不同的伤害性皮肤加热速度所产生的反应。更具体地说，低皮肤加热率引起的伤害性反应似乎是通过辣椒素敏感的C纤维伤害性感受器的激活来介导的，而高皮肤加热率似乎是通过激活其他伤害性感受器来产生的。这一假说通过电生理和行为学实验进行了验证。这份报告描述了实验结果，旨在确定选择性改变C纤维伤害性传入活动的药物治疗是否也对足部对高或低伤害性足部加热的反应产生选择性影响。这些实验的结果表明：(1)局部应用低浓度的辣椒素，从而敏化C纤维伤害性感受器，选择性地缩短对低加热率的反应潜伏期；(2)局部应用高浓度的辣椒素，使C纤维伤害性感受器减敏，选择性地延长对低加热率的反应潜伏期；(3)低剂量的全身吗啡，选择性地减弱C纤维伤害性感受器激活产生的伤害性感受，选择性地增加对低皮肤加热率的反应潜伏期。这些结果支持这样的结论：低皮肤加热率引起的足部退缩反应是由辣椒素敏感的C纤维伤害性感受器的激活介导的，而高皮肤加热率引起的足部退缩反应是由其他伤害性感受器的激活引起的。这一结论得到了伴随的电生理学研究结果的支持，该研究提供了直接的证据，即低速率的皮肤加热优先激活C纤维伤害性感受器，而高速率的皮肤加热率优先激活A三角洲伤害性感受器。
Several lines of evidence suggest that different classes of nociceptive afferents mediate the responses produced by different rates of noxious skin heating. More specifically, low skin heating rates evoke nociceptive responses that appear to be mediated by the activation of capsaicin-sensitive C-fiber nociceptors, whereas high skin heating rates appear to produce responses mediated by the activation of other nociceptors. This hypothesis was examined by both electrophysiological and behavioral experiments. This report describes the results of experiments designed to determine whether pharmacologic treatments that selectively alter the activity of C-fiber nociceptive afferents also produce selective effects on foot withdrawal responses to either high or low rates of noxious foot heating. The results of these experiments demonstrate that: (1) topical application of a low concentration of capsaicin, which sensitizes-C-fiber nociceptors, selectively decreased the latency of responses to low heating rates; (2) topical application of a high concentration of capsaicin, that desensitizes C-fiber nociceptors, selectively increased the latency of responses to low heating rates; (3) low doses of systemic morphine, which selectively attenuate nociception produced by the activation of C-fiber nociceptors, selectively increased response latencies for low skin heating rates. These results support the conclusion that foot withdrawal responses evoked by low skin heating rates are mediated by the activation of capsaicin-sensitive C-fiber nociceptors and foot withdrawal responses evoked by high skin heating rates are mediated by the activation of other nociceptors. This conclusion is supported by the results of the accompanying electrophysiological study which provides direct evidence that low rates of skin heating preferentially activate C-fiber nociceptors while high rates of skin heating preferentially activate A delta nociceptors.