The spiking output of the mouse olfactory bulb encodes large-scale temporal features of natural odor environments.
The spiking output of the mouse olfactory bulb encodes large-scale temporal features of natural odor environments.
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小鼠嗅球的尖峰输出编码自然气味环境的大规模时间特征。
DOI：
10.1101/2024.03.01.582978
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Gire,DavidH
中科院分区：
文献类型：
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作者：
Lewis,SuzanneM;Suarez,LucasM;Rigolli,Nicola;Steinmetz,NicholasA;Gire,DavidH
在自然气味环境中，气味以羽流形式传播。气味浓度动态变化在羽流的宽度和长度上以特有的方式发生变化。因此，羽流的时空动力学对于动物导航到气味来源具有信息特征。嗅球(OB)中的种群活动已被证明在一定程度上跟随羽毛上的气味浓度(Lewis等人，2021年)。然而，尚不清楚跟踪羽流动态的能力是由单个细胞驱动的，还是出现在种群水平上的。以前的研究已经探索了单个OB细胞对羽毛的单独特征的反应，但很难充分采样羽毛的完整特征空间，因为仍然不能确定导航小鼠在嗅觉引导搜索中使用了哪些特征。在这里，我们从迎风气味源释放气味，并同时记录清醒、头部固定的小鼠的气味浓度动态和细胞反应动态。我们发现，气味浓度动态的较长时间尺度特征在细胞和种群水平上都被编码。在细胞水平上，每次试验在羽流开始时都会产生反应，发出羽流开始的信号。气味浓度高的羽状物在羽状物的末端引起反应，表明羽状物偏移。虽然观察到对羽流动力学的细胞水平的跟踪很弱，但我们发现，在种群水平上，OB活动在整个羽流持续时间内区分气味和空白(准确地检测到气味的存在和不存在)。即使是大约20个OB细胞也足以准确地辨别整个羽流中的气味。我们的发现表明，气味浓度动态和高频波动的全范围并不是由OB尖峰活动编码的。相反，羽流的相对较低频率的时间特征，如羽流开始、羽流偏移、气息和空白，被表示在OB中。
In natural odor environments, odor travels in plumes. Odor concentration dynamics change in characteristic ways across the width and length of a plume. Thus, spatiotemporal dynamics of plumes have informative features for animals navigating to an odor source. Population activity in the olfactory bulb (OB) has been shown to follow odor concentration across plumes to a moderate degree (Lewis et al., 2021). However, it is unknown whether the ability to follow plume dynamics is driven by individual cells or whether it emerges at the population level. Previous research has explored the responses of individual OB cells to isolated features of plumes, but it is difficult to adequately sample the full feature space of plumes as it is still undetermined which features navigating mice employ during olfactory guided search. Here we released odor from an upwind odor source and simultaneously recorded both odor concentration dynamics and cellular response dynamics in awake, head-fixed mice. We found that longer timescale features of odor concentration dynamics were encoded at both the cellular and population level. At the cellular level, responses were elicited at the beginning of the plume for each trial, signaling plume onset. Plumes with high odor concentration elicited responses at the end of the plume, signaling plume offset. Although cellular level tracking of plume dynamics was observed to be weak, we found that at the population level, OB activity distinguished whiffs and blanks (accurately detected odor presence versus absence) throughout the duration of a plume. Even ~20 OB cells were enough to accurately discern odor presence throughout a plume. Our findings indicate that the full range of odor concentration dynamics and high frequency fluctuations are not encoded by OB spiking activity. Instead, relatively lower-frequency temporal features of plumes, such as plume onset, plume offset, whiffs, and blanks, are represented in the OB.