Mapping odorant sensitivities reveals a sparse but structured representation of olfactory chemical space by sensory input to the mouse olfactory bulb.
Mapping odorant sensitivities reveals a sparse but structured representation of olfactory chemical space by sensory input to the mouse olfactory bulb.
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DOI：
10.7554/elife.80470
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发表时间：
2022-07-21
期刊：
影响因子：
7.7
通讯作者：
Wachowiak, Matt
中科院分区：
文献类型：
--
作者：
Burton, Shawn D.;Brown, Audrey;Eiting, Thomas P.;Youngstrom, Isaac A.;Rust, Thomas C.;Schmuker, Michael;Wachowiak, Matt
在嗅觉系统中，感觉神经元汇聚到肾小球会产生气味感受器识别图。肾小球地图与感觉空间的关系尚不清楚。我们试图通过定义对气味最敏感的肾小球来更好地描述小鼠嗅觉系统中的这种关系。使用高通量气味传递和对感觉输入的超灵敏成像，我们成像了185种气味在被确定为仅激活背侧嗅球上的一个或几个肾小球的浓度下的反应。由此产生的数据集定义了低浓度状态下肾小球及其同源气味受体的调谐特性，并产生了广泛化学空间中肾小球敏感性的共识地图。肾小球的调谐非常窄，约25%只对一种气味有反应，并且对其有效气味的反应非常敏感，在亚皮摩尔到纳摩尔浓度。在这种浓度范围内的这种狭隘的调节允许基于单一的诊断气味对许多肾小球进行可靠的功能鉴定。同时，直观的气味结构特征可以很好地预测肾小球对多种气味的响应光谱，而对不同气味敏感的具有共同结构特征的肾小球在空间上是聚集的。这些结果定义了小鼠嗅觉系统对感觉空间的主要表示的潜在结构。
In olfactory systems, convergence of sensory neurons onto glomeruli generates a map of odorant receptor identity. How glomerular maps relate to sensory space remains unclear. We sought to better characterize this relationship in the mouse olfactory system by defining glomeruli in terms of the odorants to which they are most sensitive. Using high-throughput odorant delivery and ultrasensitive imaging of sensory inputs, we imaged responses to 185 odorants presented at concentrations determined to activate only one or a few glomeruli across the dorsal olfactory bulb. The resulting datasets defined the tuning properties of glomeruli - and, by inference, their cognate odorant receptors - in a low-concentration regime, and yielded consensus maps of glomerular sensitivity across a wide range of chemical space. Glomeruli were extremely narrowly tuned, with ~25% responding to only one odorant, and extremely sensitive, responding to their effective odorants at sub-picomolar to nanomolar concentrations. Such narrow tuning in this concentration regime allowed for reliable functional identification of many glomeruli based on a single diagnostic odorant. At the same time, the response spectra of glomeruli responding to multiple odorants was best predicted by straightforward odorant structural features, and glomeruli sensitive to distinct odorants with common structural features were spatially clustered. These results define an underlying structure to the primary representation of sensory space by the mouse olfactory system.