Sniff-synchronized, gradient-guided olfactory search by freely moving mice.
Sniff-synchronized, gradient-guided olfactory search by freely moving mice.
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DOI：
10.7554/elife.58523
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发表时间：
2021-05-04
期刊：
影响因子：
7.7
通讯作者：
Smear MC
中科院分区：
文献类型：
--
作者：
Findley TM;Wyrick DG;Cramer JL;Brown MA;Holcomb B;Attey R;Yeh D;Monasevitch E;Nouboussi N;Cullen I;Songco JO;King JF;Ahmadian Y;Smear MC
对于许多生物来说，寻找相关的目标，如食物或配偶，需要对环境进行主动的战略采样。寻找有气味的目标可能是能动生物进化来解决的最古老的搜索问题。虽然化学传感器导航已在微生物和无脊椎动物中得到很好的表征，但对脊椎动物的空间嗅觉知之甚少。我们已经建立了一个嗅觉搜索实验中，自由移动的小鼠导航嘈杂的浓度梯度的空气中的气味。小鼠使用浓度梯度线索解决这个任务，并且不需要立体嗅觉来表现。在执行任务期间，呼吸和鼻子运动以数十毫秒的精度同步。这种同步性在试验期间存在，而在试验间隔期间基本上不存在，这表明嗅探同步的鼻子运动是一种策略性的行为状态，而不仅仅是快速呼吸的持续伴随。为了揭示这些主动感知运动的时空结构，我们使用机器学习方法将运动轨迹解析为基本运动图案。动机分为两类，分别对应于调查状态和接近状态。调查图案精确地锁定嗅探，使得各个图案优先出现在嗅探周期的特定阶段。的allocentric结构的调查和方法表明的优势，采样的气味梯度的最尖锐的部分的两侧，与梯度传感的串行嗅探策略一致。这项工作阐明了小鼠嗅觉搜索的感觉运动策略，并指导正在进行的工作进入潜在的神经机制。
For many organisms, searching for relevant targets such as food or mates entails active, strategic sampling of the environment. Finding odorous targets may be the most ancient search problem that motile organisms evolved to solve. While chemosensory navigation has been well characterized in microorganisms and invertebrates, spatial olfaction in vertebrates is poorly understood. We have established an olfactory search assay in which freely moving mice navigate noisy concentration gradients of airborne odor. Mice solve this task using concentration gradient cues and do not require stereo olfaction for performance. During task performance, respiration and nose movement are synchronized with tens of milliseconds precision. This synchrony is present during trials and largely absent during inter-trial intervals, suggesting that sniff-synchronized nose movement is a strategic behavioral state rather than simply a constant accompaniment to fast breathing. To reveal the spatiotemporal structure of these active sensing movements, we used machine learning methods to parse motion trajectories into elementary movement motifs. Motifs fall into two clusters, which correspond to investigation and approach states. Investigation motifs lock precisely to sniffing, such that the individual motifs preferentially occur at specific phases of the sniff cycle. The allocentric structure of investigation and approach indicates an advantage to sampling both sides of the sharpest part of the odor gradient, consistent with a serial-sniff strategy for gradient sensing. This work clarifies sensorimotor strategies for mouse olfactory search and guides ongoing work into the underlying neural mechanisms.