Collaborative Research: Evolution of the hyoid, pharynx and swallowing biomechanics in mammals

所有哺乳动物，包括人类，在舌头的底部都有一块叫做舌骨的骨头。舌骨的形状、大小和位置与头骨、下颚和喉咙肌肉有关，但我们不知道为什么舌骨表现出如此广泛的差异，它是如何进化的，它对人类正常的吞咽功能意味着什么，对涉及吞咽困难的医学疾病意味着什么，对家养动物（包括宠物和农场动物）的吞咽功能意味着什么。这项研究将使用创新的成像和计算方法来测量哺乳动物舌骨和喉咙解剖结构的变化，以及研究舌骨在吞咽过程中如何运动。这项研究将创建新的三维静态舌骨解剖数据库，以及几种哺乳动物咀嚼和吞咽时舌骨和舌头运动的数据库。这项工作将加速对人类、宠物和农场动物吞咽障碍的研究。它将为传统上在STEM领域代表性不足的本科生和研究生提供研究经验的机会。它还将通过博物馆和在线平台，向芝加哥和俄亥俄州服务欠缺的城市和农村社区开展公共科学教育和推广活动。哺乳动物的舌骨器官在形状、位置以及由骨头和韧带组成的与头盖骨的连接程度上各不相同。然而，这种变异的进化和功能意义尚不清楚，因为我们缺乏关于哺乳动物舌骨和咽形态全范围变异的基本信息，以及它与进食过程中舌骨功能变异的关系。舌骨运动被认为在吞咽中起重要作用，但不同舌骨解剖结构的哺乳动物是否采用相同或不同的吞咽机制仍有待确定。本研究旨在(1)全面记录哺乳动物进化支系Euarchontoglires和Laurasiatheria的舌骨链变异；(2)量化舌骨链形态不同的物种的舌骨链解剖与舌、咽（喉）软组织解剖之间的关系；(3)确定舌骨、舌和咽解剖的种间变异是否与吞咽过程中舌舌生物力学的显著差异有关。目的(1)和(2)将通过显微计算机断层扫描（CT）和弥散碘增强CT对我们的焦点分支的代表性物种的头骨、舌骨和咽部进行处理，这些物种显示了舌骨解剖的完整范围。目的(3)将使用xrom （x射线运动形态学重建）工作流来收集三种Euarchontoglires和三种Laurasiatheria的舌功能的高分辨率3D肌肉骨骼运动学。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。

All mammals, including humans, have a bone at the base of the tongue called the hyoid bone. The hyoid bones vary in shape, size and position relative to the skull, jaws, and the muscles of the throat, but we do not know why the hyoid bones show such wide variation, how it evolved, what it means for normal swallowing function in humans, for medical disorders involving difficulty swallowing, and for swallowing function in domesticated animals (including pets and farm animals). This research will use innovative imaging and computational methods to measure the variation in hyoid and throat anatomy in mammals, as well as to study how the hyoid moves during swallowing. The research will create novel databases of three-dimensional static hyoid anatomy and of hyoid and tongue movements during chewing and swallowing in several species of mammals. The work will accelerate research into swallowing disorders in humans, their pets and in farm animals. It will provide opportunities for research experiences for undergraduate and graduate students traditionally under-represented in STEM fields. It will also engage in public science education and outreach, through museums and online platforms, to underserved urban and rural communities in Chicago and Ohio.The hyoid apparatus of mammals varies in shape, position, and the degree to which its connection to the cranium is composed of bones and ligaments. However, the evolutionary and functional significance of this variation is unknown because we lack basic information on the full range of variation in hyoid and pharynx morphology among mammals, and its relationship to variation in hyoid function during feeding. Hyoid movement is thought to play an important role in swallowing, but whether mammals with different hyoid anatomy employ the same or different swallowing mechanisms remains to be established. The proposed research aims to (1) document the full range of hyoid chain variation in the mammal clades Euarchontoglires and Laurasiatheria, (2) quantify relationships between hyoid chain anatomy and anatomy of the soft tissues of the tongue and pharynx (throat) in species with diverse hyoid chain morphologies, and (3) determine whether interspecific variation in hyoid, lingual and pharyngeal anatomy is associated with significant differences in hyolingual biomechanics during swallowing. Aims (1) and (2) will be addressed using micro-computed tomography (CT) and diffusible-iodine contrast enhanced CT of the skulls, hyoids and pharynges of representative species of our focal clades that show the full range of hyoid anatomy. Aim (3) will be addressed using the XROMM (X-Ray Reconstruction of Moving Morphology) workflow to collect high-resolution 3D musculo-skeletal kinematics of hyolingual function in three species of Euarchontoglires and three species of Laurasiatheria.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.