Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin
Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin
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DOI：
10.1152/jn.1999.81.6.2753
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发表时间：
1999-06-01
影响因子：
2.5
通讯作者：
Wessberg, J
中科院分区：
文献类型：
--
作者：
Vallbo, ÅB;Olausson, H;Wessberg, J
无髓鞘传入事件构成了编码人类毛皮肤触觉刺激的第二系统。中国生物医学工程学报，32(2):559 - 563,1999。利用微神经摄影技术记录了支配人类受试者前臂皮肤的无髓鞘传入神经的脉冲。选择对无害皮肤变形有反应的单位。样本（n = 38）被分为低阈值单元（n = 27）和高阈值单元（n = 11），基于三个显著特征，即皮肤变形阈值，对无害皮肤变形的反应大小，以及对尖锐和钝性刺激的不同反应。根据低阈值单元的反应特性，我们暂时将其称为触觉传出单元，这强烈表明它们编码了触觉刺激的某些特征。它们在许多方面表现出与其他哺乳动物的低阈值c -机械感受单位相似的功能特性。然而，延迟加速，以前没有证明，被观察到对长期无害的凹痕的反应。结论是，人类多毛皮肤是由一个高度敏感的机械感受单位系统支配的，该系统具有无髓鞘的传入神经，类似于先前在其他哺乳动物中描述的系统。证实该系统存在于前臂皮肤中，而不仅仅是在最初被发现的面部区域，这表明该系统在很大程度上是普遍分布的，尽管有迹象表明触觉C传入可能在肢体的非常远端部分缺乏。该系统的功能作用仍有待评估，尽管感觉器官的生理特性引起了人们的猜测，即慢触觉系统可能与边缘功能的关系比与认知和运动功能的关系更密切。
Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin. J. Neurophysiol. 81: 2753-2763, 1999. Impulses were recorded from unmyelinated afferents innervating the forearm skin of human subjects using the technique of microneurography. Units responding to innocuous skin deformation were selected. The sample (n = 38) was split into low-threshold units (n = 27) and high-threshold units (n = 11) on the basis of three distinctive features, i.e., thresholds to skin deformation, size of response to innocuous skin deformation, and differential response to sharp and blunt stimuli. The low-threshold units provisionally were denoted tactile efferents on the basis of their response properties, which strongly suggest that they are coding some feature of tactile stimuli. They exhibited, in many respects, similar functional properties as described for low-threshold C-mechanoreceptive units in other mammals. However, a delayed acceleration, not previously demonstrated, was observed in response to long-lasting innocuous indentations. It was concluded that human hairy skin is innervated by a system of highly sensitive mechanoreceptive units with unmyelinated afferents akin to the system previously described in other mammals. The confirmation that the system is present in the forearm skin and not only in the face area where it first was identified suggests a largely general distribution although there are indications that the tactile C afferents may be lacking in the very distal parts of the limbs. The functional role of the system remains to be assessed although physiological properties of the sense organs invite to speculations that the slow tactile system might have closer relations to limbic functions than to cognitive and motor functions.