Cutaneous mechanosensory neurons are activated by mechanical loads applied to the skin, and these stimuli are proposed to generate mechanical strain within sensory neurons. Using a microfluidic device to deliver controlled stimuli to intact animals and large, immobile, and fluorescent protein-tagged mitochondria as fiducial markers in the touch receptor neurons (TRNs), we visualized and measured touch-induced mechanical strain in Caenorhabditis elegans worms. At steady state, touch stimuli sufficient to activate TRNs induce an average strain of 3.1% at the center of the actuator and this strain decays to near zero at the edges of the actuator. We also measured strain in animals carrying mutations affecting links between the extracellular matrix (ECM) and the TRNs but could not detect any differences in touch-induced mechanical strain between wild-type and mutant animals. Collectively, these results demonstrate that touching the skin induces local mechanical strain in intact animals and suggest that a fully intact ECM is not essential for transmitting mechanical strain from the skin to cutaneous mechanosensory neurons.

中文翻译：

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体感神经元中触摸诱导的机械应变独立于秀丽隐杆线虫的细胞外基质突变。

皮肤机械感觉神经元被施加于皮肤的机械负荷激活，并且提出了这些刺激以在感觉神经元内产生机械应变。我们使用微流控设备向完整的动物以及大型，固定和荧光蛋白标记的线粒体提供了受控的刺激，作为触觉感受器神经元（TRNs）中的基准标记，我们观察并测量了秀丽隐杆线虫的触觉诱发的机械应变。在稳定状态下，足以激活TRN的触摸刺激在致动器的中心引起3.1％的平均应变，并且该应变在致动器的边缘衰减至接近零。我们还测量了携带突变的动物的应变，这些突变影响细胞外基质（ECM）和TRN之间的联系，但无法检测野生型和突变动物在触摸感应机械应变中的任何差异。总的来说，这些结果表明，触摸皮肤会在完整的动物中引起局部机械应变，并表明完全完整的ECM对于将机械应变从皮肤传递到皮肤机械感觉神经元不是必需的。