Logan David R, Hall Jesse, Bianchi Laura
Department of Physiology and Biophysics, University of Miami, Miami, FL, United States.
Front Cell Neurosci. 2024 Feb 16;18:1367476. doi: 10.3389/fncel.2024.1367476. eCollection 2024.
During touch, mechanical forces are converted into electrochemical signals by tactile organs made of neurons, accessory cells, and their shared extracellular spaces. Accessory cells, including Merkel cells, keratinocytes, lamellar cells, and glia, play an important role in the sensation of touch. In some cases, these cells are intrinsically mechanosensitive; however, other roles include the release of chemical messengers, the chemical modification of spaces that are shared with neurons, and the tuning of neural sensitivity by direct physical contact. Despite great progress in the last decade, the precise roles of these cells in the sense of touch remains unclear. Here we review the known and hypothesized contributions of several accessory cells to touch by incorporating research from multiple organisms including , , mammals, avian models, and plants. Several broad parallels are identified including the regulation of extracellular ions and the release of neuromodulators by accessory cells, as well as the emerging potential physical contact between accessory cells and sensory neurons via tethers. Our broader perspective incorporates the importance of accessory cells to the understanding of human touch and pain, as well as to animal touch and its molecular underpinnings, which are underrepresented among the animal welfare literature. A greater understanding of touch, which must include a role for accessory cells, is also relevant to emergent technical applications including prosthetics, virtual reality, and robotics.
在触觉过程中，机械力通过由神经元、辅助细胞及其共享的细胞外空间组成的触觉器官转化为电化学信号。辅助细胞，包括默克尔细胞、角质形成细胞、板层细胞和神经胶质细胞，在触觉感受中发挥着重要作用。在某些情况下，这些细胞本身具有机械敏感性；然而，其他作用包括化学信使的释放、与神经元共享空间的化学修饰以及通过直接物理接触调节神经敏感性。尽管在过去十年中取得了很大进展，但这些细胞在触觉中的精确作用仍不清楚。在这里，我们通过整合来自多种生物（包括 、 、哺乳动物、鸟类模型和植物）的研究，综述了几种辅助细胞对触觉的已知和假设贡献。我们确定了几个广泛的相似之处，包括辅助细胞对细胞外离子的调节和神经调质的释放，以及辅助细胞与感觉神经元之间通过系链形成的新的潜在物理接触。我们更广阔的视角体现了辅助细胞对于理解人类触觉和疼痛以及动物触觉及其分子基础的重要性，而这些在动物福利文献中较少被提及。对触觉的更深入理解（其中必须包括辅助细胞的作用）也与新兴技术应用相关，包括假肢、虚拟现实和机器人技术。
