Specialized Mechanosensory Nociceptors Mediating Rapid Responses to Hair Pull
Specialized Mechanosensory Nociceptors Mediating Rapid Responses to Hair Pull
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DOI：
10.1016/j.neuron.2017.07.024
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发表时间：
2017-08-16
期刊：
影响因子：
16.2
通讯作者：
Chesler, Alexander T.
中科院分区：
文献类型：
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作者：
Ghitani, Nima;Barik, Arnab;Chesler, Alexander T.
躯体感觉系统为动物提供了检测、区分和响应各种热、机械和刺激性刺激的能力。虽然在定义温度感觉和温柔触摸的神经元类别方面取得了进展，但对机械疼痛特异性神经元的了解较少。在这里，我们使用体内功能成像来识别一类由高阈值机械刺激（HTMR）选择性激活的皮肤感觉神经元。我们发现，它们的光遗传学激发引起快速的保护和回避行为。与其他伤害感受器不同，这些HTMR是快速传导的Ad纤维，具有高度专业化的圆周末端，包裹着单个毛囊的基部。值得注意的是，我们发现Ad-HTMRs支配独特但重叠的领域，并且可以通过像拉动一根头发一样精确的刺激来激活。总之，这类Ad-HTMR的独特特征似乎是针对机械性疼痛的准确和快速定位而优化的。
The somatosensory system provides animals with the ability to detect, distinguish, and respond to diverse thermal, mechanical, and irritating stimuli. While there has been progress in defining classes of neurons underlying temperature sensation and gentle touch, less is known about the neurons specific for mechanical pain. Here, we use in vivo functional imaging to identify a class of cutaneous sensory neurons that are selectively activated by high-threshold mechanical stimulation (HTMRs). We show that their optogenetic excitation evokes rapid protective and avoidance behaviors. Unlike other nociceptors, these HTMRs are fast-conducting Ad-fibers with highly specialized circumferential endings wrapping the base of individual hair follicles. Notably, we find that Ad-HTMRs innervate unique but overlapping fields and can be activated by stimuli as precise as the pulling of a single hair. Together, the distinctive features of this class of Ad-HTMRs appear optimized for accurate and rapid localization of mechanical pain.