Collaborative Research: Reconstructing Airflow in the Nasal Cavity of Mammals

哺乳动物的鼻子里有一组复杂的薄如纸的骨头，称为鼻甲。鼻甲骨参与嗅觉和调节空气，但它们的功能还不清楚。这是真实的，尽管事实上，更好地了解鼻腔解剖结构和功能是必不可少的进步，在预测人体气道中的颗粒沉积，改善鼻内药物输送，并开发人工嗅探器检测危险物质，如爆炸物。 关于鼻甲骨功能的一些最重要的问题涉及通过鼻子的气流方面。它们是如何将空气引导到嗅觉区域的？ 呼吸和嗅觉有不同的途径吗？不同物种在鼻甲骨结构上的差异能告诉我们什么关于气味接收效率和热量和水的保存？为了回答这些问题，该项目汇集了来自生物学和工程学两个不同领域的科学家，以促进我们对呼吸和嗅觉的理解。通过结合现代高分辨率医学成像，最先进的流动模型和鼻软组织分布数据，这种跨学科合作将是第一个应用新型计算建模工具（例如，3-D解剖重建、计算流体动力学[CFD]）和实验测量技术（例如，使用解剖学上正确的透明物理模型）来开发鼻子的新的形状-功能关系。为此，将根据完整头部的磁共振图像（MRI）、骨性鼻甲的计算机断层扫描（CT）扫描以及嗅觉与呼吸组织分布的实验室分析，重建五种哺乳动物的3-D鼻解剖结构。为了使未来的研究，成对组的MRI扫描的完整的头部和CT扫描的清洁的头骨将被用来开发一种方法，纠正CT衍生的图像数据的干燥头骨标本的鼻粘膜的情况下。这将允许仅使用现有博物馆收藏的头骨而不是完整的头部来研究鼻气流，从而大大扩展了可以研究的物种和功能的范围。最后，为了增加对鼻功能的了解，除了受到最多关注的两个相对较短的鼻部群体，即，灵长类动物和食肉动物，10-15有蹄类动物的鼻甲骨将重建干头骨的CT扫描和分析的鼻甲骨尺寸。 将生成11-16种哺乳动物头骨的10，000多个CT切片，以及三种哺乳动物完整头部的成对MRI扫描和头骨的CT扫描。所有新的扫描将存放在德克萨斯大学奥斯汀分校的NSF数字形态学图书馆（www.digimorph.org），供公众在获得该项目资助后5年内访问。同样，本研究期间开发的所有数值计算流体动力学模型将通过PI建立并由宾夕法尼亚州立大学托管的网站提供。作为该项目的一部分，许多研究生和本科生将接受生物学和工程学方面的培训。 少数民族研究生和本科生将通过每个机构的专门项目招募，调查人员将继续向高中生和普通观众进行宣传。

The mammalian nose houses a complex set of paper-thin bones known as turbinals. Turbinals are involved in both the sense of smell and conditioning inspired air, and yet their function is not well understood. This is true despite the fact that a better knowledge of nasal anatomy and function is essential for progress in predicting particulate deposition in human airways, improving intranasal drug delivery, and the development of artificial sniffers for the detection of dangerous substances such as explosives. Some of the most important questions about turbinal function concern aspects of airflow through the nose. How do they direct air to the olfactory region? Are there separate pathways for respiration and olfaction? What can differences among species in the architecture of the turbinals tell us about the efficiency of odorant reception and heat and water conservation? To answer these questions, this project brings together scientists from two disparate fields, biology and engineering, to advance our understanding of respiration and olfaction. By combining modern high-resolution medical imaging, state-of-the-art models of flow, and data on nasal soft tissue distribution, this cross-disciplinary collaboration will be the first to apply novel computational modeling tools (e.g., 3-D anatomical reconstruction, computational fluid dynamics [CFD]) and experimental measurement techniques (e.g., use of anatomically-correct transparent physical models) to develop new form-function relationships for the nose. To do so, the 3-D nasal anatomy of five mammal species will be reconstructed from magnetic resonance images (MRI) of intact heads, computed tomography (CT) scans of their bony turbinals, and laboratory analysis of the distribution of olfactory vs. respiratory tissue. To enable future studies, paired sets of MRI scans of intact heads and CT scans of the cleaned skulls will be used to develop a method that corrects CT-derived image data of dry skull specimens for the absence of nasal mucosa. This will permit the study of nasal airflow using existing museum collections of skulls alone rather than intact heads, thereby greatly expanding the range of species and function that can be studied. Finally, to increase knowledge of nasal function beyond the two relatively short-snouted groups that have received the most attention, viz., primates and carnivores, the turbinals of 10-15 ungulate species will be reconstructed from CT scans of dry skulls and analyzed for turbinal dimensions. Over 10,000 CT slices of the skulls of 11-16 species of mammals, as well as paired sets of MRI scans of intact heads and CT scans of skulls for three individual mammals will be generated. All new scans will be deposited in the NSF Digital Morphology Library at the University of Texas, Austin (www.digimorph.org) for public access within 5 years of receiving funding for this project. Similarly, all of the numerical CFD models developed during this study will be made available via a website to be established by the PIs and hosted by Penn State University. Numerous graduate students and undergraduates will be trained in aspects of both biology and engineering as part of this project. Minority graduate and undergraduate students will be recruited through dedicated programs at each institution, and the investigators will continue their ongoing outreach efforts to high school students and lay audiences.