Mammalian behavioral discrimination and neural processing of naturalistic odor plumes based on intermittency

项目总结 哺乳动物使用气味导航来避免有害的环境危险，寻找食物来源，定位配偶，以及 逃脱捕食者--生存的关键行为。自然界中的气味通常由湍流携带，产生 气味羽流具有复杂的时空结构。间歇性是一个流体动力学参数，它可以量化 这种波动的性质作为时间的一部分气味出现在羽流中的某个点上。间歇性减少 与气味来源的距离增加，并可提供有关来源接近的重要信息。 这样的气味信息必须由动物采集，通过嗅觉系统整合，最终由驱动力 导航。哺乳动物通过嗅觉来调节气味采样，快速采样可能支持 在羽流的低间歇性部分检测稀疏气味气味。此外，嗅觉感觉神经元 (OSN)能够具有快速响应特性，该特性有利于检测短暂的气味呈现为 以及对允许检测气味变化的持续气味呈现的响应适应 风景。尽管动态气味羽流在自然界中普遍存在，但大多数研究都集中在嗅觉上 静电气味的处理。这项建议的目的是检查小鼠是否可以使用时间特性 用于导航的气味羽流，并确定它们对这些动态气味序列的神经行为反应。 这项提议将检验这样一个假设，即小鼠可以使用间歇性来导航气味羽流，并且 嗅探和OSN响应特性的调制使得能够检测在羽状物外围的气味存在 以及接近污染源的气味环境的变化。在前期工作中，对小鼠进行了一项任务的训练 他们区分气味序列，其中一些直接从气味羽流中采样，使用 间歇性的。他们用来执行这项任务的抽样策略被假设为嗅探的增加 在气味呈现期间以低间歇性检测稀疏气味的频率。这一点将被确定 通过测量任务期间的嗅探频率。此外，OSN的响应将被量化以检验假设 在低间歇性时，需要对每一种气味的强烈反应来进行间歇性辨别(AIM 1)。为了定义OSN对波动气味的响应适应，OSN响应幅度降低到 在表现出一系列嗅觉的小鼠中，将对不断增加的间歇性气味进行量化 频率(目标2)。如果导航依赖于可靠地检测到外围的气味存在并改变 在接近来源的气味环境中，OSN对低间歇性刺激的反应可能是敏感的 许多喘息和适应可能只有在高间歇性刺激下才会发生。这项提案将提供对 哺乳动物如何解释嗅觉信息以定位基本的气味来源。这项工作与 NIDCD的使命是了解嗅觉的正常过程，因为它对无数的日常功能至关重要。

PROJECT SUMMARY Mammals use odor navigation to avoid noxious environmental dangers, find food sources, locate mates, and escape predators- critical behaviors for survival. Odors in nature are often carried by turbulent air flow, producing odor plumes with complex spatiotemporal structure. Intermittency is a fluid dynamics parameter that quantifies this fluctuating nature as the fraction of time odor is present at a point within the plume. Intermittency decreases with increased distance from an odor source and may provide important information about source proximity. Such odor information must be sampled by animals, integrated by the olfactory system, and ultimately, drive navigation. Mammals modulate odor sampling through sniffing, and rapid sampling can possibly support the detection of sparse odor whiffs at low intermittency sections of a plume. In addition, olfactory sensory neurons (OSNs) are capable of rapid response properties that are beneficial for detection of fleeting odor presentation as well as response adaptation to persistent odor presentation that allows for detection of changes in the odor landscape. Although dynamic odor plumes are prevalent in nature, most studies have focused on olfactory processing of static odors. The objective of this proposal is to examine if mice can use temporal properties of odor plumes for navigation and to determine their neurobehavioral responses to these dynamic odor sequences. This proposal will test the hypothesis that mice can use intermittency to navigate odor plumes and that modulation of sniffing and OSN response properties enable detection of odor presence at the plume periphery and changes in the odor environment close to the source. In preliminary work, mice were trained on a task in which they discriminate between odor sequences, some directly sampled from an odor plume, using intermittency. The sampling strategies they use to perform this task are hypothesized as an increase in sniff frequency during odor presentation at low intermittencies to detect sparse odor whiffs. This will be determined by measuring sniff frequency during the task. Moreover, OSN responses will be quantified to test the hypothesis that at low intermittencies, robust responses to each odor whiff are needed for intermittency discrimination (Aim 1). To define OSN response adaptation to fluctuating odors, decreases in OSN response amplitude to consecutive odor whiffs across increasing intermittency will be quantified in mice displaying a range of sniff frequencies (Aim 2). If navigation depends on reliable detection of odor presence at the periphery and changes in odor environment close to the source, OSN response to low intermittency stimuli may be sensitive across many whiffs and adaptation may only occur with high intermittency stimuli. This proposal will provide insight into how mammals interpret olfactory information to localize essential odor sources. This work is well-aligned with the NIDCD mission to understand the normal processes of smell as it is critical to countless everyday functions.