Collaborative Research: NCS-FO: A Computational Neuroscience Framework for Olfactory Scene Analysis within Complex Fluid Environments

大多数动物在湍流空气或水环境中生存，并且是可以在复杂湍流条件下量化气味信号以跟踪和找到气味来源（例如食物，配偶等）的活生生的证据。然而，我们的工程知识仍然无法制定简单有效的测量方法，使人造系统能够预测，导航和利用这种湍流的特性来定位化学释放的来源。该项目建立在最近令人兴奋的生物体神经生物学计算模型的基础上，该模型预测龙虾不仅能够估计气味的浓度，还能够估计自上次遇到气味以来的时间。龙虾通过在一群嗅觉受体神经元（ORN）之间使用整体竞争来实现这一点，称为“爆裂ORN”。Bursting ORN用于计算自上次遇到气味以来的时间，其沿着浓度，可以提供到气味源的距离的测量。这项研究将寻求增加对ORN如何感知气味浓度和气味羽流内测量的气味浓度的理解，以及这些信息如何整合到龙虾的大脑中。另一个主要目标是开发新的基于神经生物学的理论，以寻找气味源，这些气味源可以在人类工程的自主水下航行器中实现，这些自主水下航行器能够在湍流化学羽流中航行。这项工作将加强新一代电子鼻在国防和民用方面的应用，以跟踪自然或人为灾害中的化学品。通过这个项目，也有很好的资源和推广机会，在流体动力学，神经科学，计算机工程和信息处理的交叉点的学生的综合教育和培训。该项目将通过佛罗里达大学的创新脑机接口中心进行协调，并将为本科生和研究生提供研究机会，促进神经技术创新，并促进创业活动，以创建潜在的未来初创公司。这项研究汇集了一个多学科和互补的专家团队，包括流体动力学家，神经生物学家，一位电气工程师，他的目标非常明确，那就是理解和利用湍流中的嗅觉场景分析。该研究将包括化学羽流混合和ORN对龙虾气味遭遇的反应的实验室实验，搜索优化的理论分析，以及电子鼻的数值模拟和新的系统架构，目标是为自主水下航行器配备在湍流化学羽流中导航的能力。这将增加我们对嗅叶（第一个嗅觉中继）如何利用突发嗅觉神经元反应的理解，以及这些信息如何与嗅球中的气味特异性信息整合。此外，这项工作将提高我们的理解湍流羽动力学，以发展一个新的神经生物学为基础的理论在寻找气味源。利用从大规模羽流中获得的信息，研究人员将使用龙虾的嗅觉器官作为模型系统，以了解对这些化学传感器的物理约束，并研究气味输入的空间和时间关系在嗅觉受体神经元兴奋中的作用。这项工作将为嗅觉场景分析提供一个概念基础，与视觉和听觉相比，嗅觉场景分析仍处于起步阶段。

Most animals survive in turbulent air or water environments and are living proof that it is possible to quantify odor signals in complex turbulent flow conditions to track and find sources of odors (such as food, mates, etc.). However, our engineering knowledge is still incapable of formulating simple and effective measurements that will enable man-made systems to predict, navigate and utilize properties of this turbulent flow to locate sources of chemical release. This project builds on recent exciting computational modeling of the neurobiology of organisms by the proposers, which predict that lobsters are capable of estimating not only the concentration of odors but also the time since the last odor was encountered. Lobsters accomplish this by using ensemble competition across a population of olfactory receptor neurons (ORNs), called "bursting ORNs". Bursting ORNs function to compute the time since last encounter of an odor that, along with concentration, can provide a measure of the distance to the odor source. This research will seek to increase understanding of how ORNs perceive odor concentration and intermittency measured within an odor plume, and how this information is integrated within the lobster's brain. An additional major objective is to develop new neurobiology-based theories in the search for odor sources that can be implemented within human-engineered autonomous underwater vehicles that have the ability to navigate in turbulent chemical plumes. This work will enhance defense and civilian applications of a new generation of electronic noses for tracking chemicals in natural or man-initiated disasters. Through this project, there are also excellent resources and outreach opportunities for integrated education and training of students at the intersection of fluid dynamics, neuroscience, computer engineering and information processing. Outreach will be coordinated through the Center of Innovative Brain Machine Interfaces at the University of Florida and will provide opportunities for undergraduate and graduate research, promote neurotechnology innovations, and foster entrepreneurship activities in order to create potential future start-up companies.This research brings together a multidisciplinary and complementary team of experts, including a fluid dynamicist, a neurobiologist, and an electrical engineer with the very clear goal of understanding and exploiting olfactory scene analysis in turbulent flow. The research will include laboratory experiments of chemical plume mixing and ORN responses to odor encounters by lobsters, theoretical analysis of search optimization, as well as numerical simulations and novel system architecture for electronic noses with the goal of equipping autonomous underwater vehicles with the ability to navigate in turbulent chemical plumes. This will increase our understanding of how bursting olfactory neuron responses are exploited by the olfactory lobe, the first olfactory relay, and how this information is integrated with the odor specific information in the olfactory bulb. Moreover, this work will enhance our understanding of turbulent plume dynamics in order to develop a new neurobiology-based theory in the search for odor sources. Using information obtained from a large-scale plume, the researchers will use the olfactory organs of the lobster as a model system to understand the physical constraints placed on these chemosensors and examine the role of spatial and temporal relationships of odor inputs in the excitation of olfactory receptor neurons. The work will provide a conceptual substrate for olfactory scene analysis informed by neurobiology, which is still in its infancy compared with vision and audition.