Molecular mechanism of touch sensitivity in the Schnauzenorgan of the Elephant Nose Fish

这项研究的重点是触觉——包括人类在内的所有动物都具有的一种基本生理能力，它赋予了动物通过皮肤感知物质世界的能力。触觉对于在环境中导航、操作工具、操纵物体、探测食物的质地、感知母亲关怀的抚摸或捕食者的咬伤都是必不可少的。尽管触觉对动物生存的各个方面都很重要，但它仍然是最不为人所知的感官之一。事实上，我们对触觉是如何被检测到的，以及这种能力在不同物种的进化过程中是如何变化的，知之甚少。该项目旨在通过研究象鼻鱼（Gnathonemus petersii）来填补我们对触觉知识的空白。G. petersii是一种触觉专家，它用它灵活的下巴附属物，叫做Schnauzenorgan，以一种类似于手指的方式在浑浊的河床上寻找食物。G. petersii通过触觉而不是视觉或嗅觉寻找食物的迷人能力，为从触觉冠军的角度研究这种感觉提供了一个独特的机会。本项目将获得脊椎动物外周神经系统感觉神经元的触觉检测过程的机制见解。为了产生更广泛的影响，这项研究的结果将通过课外推广计划传播。通过将现场讲座和实验与在线课程相结合，该项目将在不同年龄的学生中传播生理学领域的科学知识，重点关注传统上在科学家中未被充分代表的种族和社会经济群体。这个项目的科学和外联部分将为研究生提供基础训练，以促进他们作为研究人员和教育工作者的发展。该项目将研究G. petersii如何在细胞和分子水平上实现机械感觉专业化。章鱼的耳蜗器官由有髓鞘的三叉神经触觉感受器支配，这些感受器以裸露的神经末梢的形式终止于皮肤，不形成具有微粒结构的复合体。本项目的目的是对一种新型机械感受器进行功能和组织学研究，并确定其触觉敏感性的分子机制。该项目将测试三叉神经节中是否含有更多的机械感受器，研究支配彼得氏家鼠Schnauzenorgan的机械感受器是否增强了感知触觉的能力，并揭示将触觉转化为兴奋的分子。为了实现这一目标，该项目将利用多学科方法，结合电生理学、组织学和生物信息学。这一研究结果将对理解脊椎动物机械敏感性的分子进化具有重要意义。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This research focuses on the sense of touch – a fundamental physiological capacity present in all animals, including humans, which endows them with the ability to sense the physical world through the skin. The sense of touch is essential for navigation in the environment, for handling tools, manipulating objects, detecting the texture of food, for sensing a mother’s caring touch or the bite of a predator. Even though the sense of touch is important for every aspect of an animal’s existence, it remains one of the least well understood senses. Indeed, we know very little about how touch is detected, and how this ability changes in different species during evolution. This project aims to fill the gap in our knowledge about the sense of touch by studying Elephant Nose Fish (Gnathonemus petersii). G. petersii is a tactile specialist animal who uses its flexible chin appendage, called the Schnauzenorgan, in a manner similar to a finger in order to find food in the bed of murky rivers. The fascinating ability of G. petersii to find food by touch rather than through vision or smell lends a unique opportunity to study this sense from the perspective of a tactile champion. This project will obtain mechanistic insights into the process of touch detection by sensory neurons of the peripheral nervous system of vertebrates. To achieve broader impact, results from this research will be disseminated through an extracurricular outreach program. By combining in-person lectures and experiments with online classes, this outreach program will disseminate scientific knowledge in the area of physiology among students of different ages, with an emphasis on the ethnic and socioeconomic groups traditionally underrepresented among scientists. The scientific and outreach components of this project will provide fundamental training for graduate students to foster their development as researchers and educators.This project will investigate how G. petersii achieves mechanosensory specialization at cellular and molecular levels. The Schnauzenorgan of G. petersii is innervated by myelinated trigeminal touch receptors, which terminate in the skin as bare nerve endings, without forming a complex with corpuscular structures. The goal of this project is to perform functional and histological investigation of the novel type of mechanoreceptors from the Schnauzenorgan of G. petersii, and identify the molecular mechanism of its touch sensitivity. The project will test whether the trigeminal ganglia of G. petersii contains an expanded population of mechanoreceptors, investigate whether mechanoreceptors innervating the Schnauzenorgan of G. petersii have augmented ability to sense touch, and reveal molecules that convert touch into excitation. To achieve this, the project will utilize a multidisciplinary approach, combining electrophysiology, histology and bioinformatics. Results from this proposal will be essential for understanding molecular evolution of mechanosensitivity in vertebrates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.