To understand how odors are represented in the initial stages of the mammalian olfactory system, we have developed a platform for efficiently mapping olfactory sensory neuron (OSN) input to glomeruli of the mouse olfactory bulb (OB). Using a high-throughput odorant delivery device (see ‘Olfactometry’) combined with the ultrasensitive genetically-encoded reporter GCaMP6s expressed in all OSNs, we have imaged OSN responses across glomeruli of the dorsal OB for 185 odorants, using odorant concentrations (1e-14 – 1e-9 M) chosen to identify the highest-sensitivity glomeruli for each odorant. The resulting datasets define consensus maps of odorant sensitivity across the dorsal OB, and also allow for the functional identification of numerous glomeruli based on extremely simple response criteria. A description and analysis of these datasets, with surprising findings regarding the sensitivity and selectivity of sensory input to glomeruli, is published in eLife (Burton et al., 2022).

 

We have compiled the data into two resources that should be useful references for further investigation of odor representations in the mouse brain. These are freely downloaded using the links below. Raw data underlying these response maps, as well as Matlab-based GUIs for visualizing and browsing the datasets, is available on our Github site.  

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Functional atlas of odorant responses

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Atlas and odorant lookup table for functionally-identified glomeruli

 

Odorant identity and concentration information for functional atlases

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Data credits: Shawn Burton, Matt Wachowiak

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