Institute for Building Materials, Swiss Federal Institute of Technology Zurich (ETH Zürich), 8093 Zurich, Switzerland.
Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland.
Int J Mol Sci. 2020 Dec 30;22(1):280. doi: 10.3390/ijms22010280.
Insects fall prey to the () when they touch the sensory hairs located on the flytrap lobes, causing sudden trap closure. The mechanical stimulus imparted by the touch produces an electrical response in the sensory cells of the trigger hair. These cells are found in a constriction near the hair base, where a notch appears around the hair's periphery. There are mechanosensitive ion channels (MSCs) in the sensory cells that open due to a change in membrane tension; however, the kinematics behind this process is unclear. In this study, we investigate how the stimulus acts on the sensory cells by building a multi-scale hair model, using morphometric data obtained from μ-CT scans. We simulated a single-touch stimulus and evaluated the resulting cell wall stretch. Interestingly, the model showed that high stretch values are diverted away from the notch periphery and, instead, localized in the interior regions of the cell wall. We repeated our simulations for different cell shape variants to elucidate how the morphology influences the location of these high-stretch regions. Our results suggest that there is likely a higher mechanotransduction activity in these 'hotspots', which may provide new insights into the arrangement and functioning of MSCs in the flytrap.
昆虫接触到捕蝇草叶片上的感觉毛时，就会成为（）的猎物，导致突然的陷阱关闭。触摸所产生的机械刺激会在触发毛的感觉细胞中产生电响应。这些细胞位于毛发基部附近的一个收缩处，在毛发周围出现一个缺口。感觉细胞中有机械敏感离子通道（MSCs），由于膜张力的变化而打开；然而，这个过程背后的运动学尚不清楚。在这项研究中，我们通过使用从μ-CT 扫描中获得的形态测量数据来构建多尺度毛发模型，研究刺激如何作用于感觉细胞。我们模拟了单次触摸刺激，并评估了由此产生的细胞壁拉伸。有趣的是，该模型表明，高拉伸值从缺口周围转移，而是集中在细胞壁的内部区域。我们对不同的细胞形状变体重复了我们的模拟，以阐明形态如何影响这些高拉伸区域的位置。我们的结果表明，在这些“热点”中，很可能存在更高的机械转导活性，这可能为捕蝇草中 MSCs 的排列和功能提供新的见解。
