Sensory receptors with unmyelinated (C) fibers innervating the skin of the rabbit's ear.
Sensory receptors with unmyelinated (C) fibers innervating the skin of the rabbit's ear.
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DOI：
10.1152/jn.1985.54.3.491
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发表时间：
1985-09
影响因子：
2.5
通讯作者：
V. Shea;E. Perl
中科院分区：
文献类型：
--
作者：
V. Shea;E. Perl
兔子耳大神经的无髓鞘（C）纤维的皮肤接受特性通过单单元记录来确定。大多数C纤维单元可以通过皮肤刺激而兴奋，并且这些感觉单元根据其皮肤感受野对机械和热刺激的反应分为三大类：低阈值机械感受器、伤害感受器或特定温度感受器。大多数传入元件是伤害性的，所有伤害性感受器都对强烈的机械刺激有反应。三种类型的伤害感受器可以通过它们对热刺激的反应来区分。多模式伤害感受器对 40-55 摄氏度阈值的热作出反应，并且在其感受野受到有害加热后通常表现出增强的反应或敏化。高阈值机械感受器在有害皮肤刺激之前未能对热做出迅速反应，然而，这引起了随后的背景活动或对热的敏感性。第三种伤害感受器对寒冷有反应，但对热没有反应。低阈值机械感受器通过对其感受野的非常温和、缓慢移动的机械刺激做出快速反应来识别，并且很容易与因其较低机械阈值而被归类为伤害性感受器的任何元素区分开来。快速无害的升温或降温会兴奋一些低阈值机械感受器。特定的温度感受器，无论是加热型还是冷却型，都很罕见，对机械刺激不敏感，并对温度的微小变化做出反应。与大多数伤害感受器的特征——热敏化相反，特定的温热感受器在其感受野受到有害加热后表现出抑制的热反应。这些结果进一步证明了支配不同物种毛状皮肤的 C 纤维受体的相似性。描述了与过去报告的一些差异和附加功能。
The cutaneous receptive properties of unmyelinated (C) fibers of the rabbit's great auricular nerve were determined by single-unit recordings. The majority of C-fiber units could be excited by cutaneous stimulation, and such sensory units fell into three major categories on the basis of responses to mechanical and thermal stimulation of their cutaneous receptive fields: low-threshold mechanoreceptors, nociceptors, or specific thermoreceptors. The majority of afferent elements were nociceptive, and all nociceptors responded to strong mechanical stimulation. Three types of nociceptors could be distinguished by their responses to thermal stimuli. Polymodal nociceptors responded to heat with thresholds of 40-55 degrees C and typically displayed enhanced responses or sensitization after noxious heating of their receptive fields. High-threshold mechanoreceptors failed to respond promptly to heat before noxious cutaneous stimulation which, however, elicited subsequent back-ground activity or sensitivity to heat. A third type of nociceptor responded to cold but not to heat. Low-threshold mechanoreceptors were identified by their brisk responses to very gentle, slowly moving mechanical stimulation of their receptive fields, and were readily distinguished from any element classified as nociceptive by their lower mechanical thresholds. Rapid innocuous warming or cooling excited some of the low-threshold mechanoreceptors. Specific thermoreceptors, both warming and cooling types, were rare, insensitive to mechanical stimulation, and responded to very slight changes in temperature. In contrast to the sensitization to heat, which was characteristic of most nociceptors, specific warming receptors displayed depressed thermal responses after noxious heating of their receptive fields. These results provide further evidence of the similarity of C-fiber receptors innervating hairy skin of different species. Some differences from past reports and additional features are described.