New work in mice finds that smell receptors are neatly organised into tight, type-specific bands, aligning with sensory maps in the brain.
15 May 2026
By Emma Young
Our brains use spatial maps to make sense of sound, touch, and visual signals. Different frequencies of sound stimulate different regions of the cochlea, for example, and this 'sound map' is preserved as the signals from the ear make their way through to the brain's cortex.
Whether smells are mapped in a similar way has not been clear, however. "Addressing this foundational question is critical for our understanding of the sense of smell," note the authors of recent paper in Cell. Their work, along with another paper in the same journal, now suggests that this is indeed the case for mice, opening up the possibility that we humans may use scent maps, too.
Human noses contain millions of olfactory neurons, each one tipped with one of about 400 different types of olfactory receptor. Each type of receptor binds to one specific smelly molecule. When this happens, the neuron sends a signal to the brain.
Mice have a very similar system, but with about 1,172 different types of functional olfactory receptor. For their study, David H. Brann at Harvard Medical School and colleagues studied about five million olfactory neurons from hundreds of individual mice. They identified which smell receptor was expressed by which neuron, and mapped their locations within the nasal lining. Their analysis showed that, contrary to prior assumptions, each individual type of receptor exists in a 'stripe' within the nasal lining, and each stripe overlaps with other receptor stripes. This work reveals that the location of receptor types is highly organised, and forms a distinct map.
In the second study, a team led by Bogdan Bintu, who was at Harvard University at the time, and is now at the University of California, San Diego created a complementary atlas, showing the organisation of olfactory receptors within the mouse nose. The team also looked at where, exactly, the long neurons that express each type of receptor end up in the olfactory bulb, the smell hub of the brain. They found that each type ends up in a very specific location. "What's beautiful is how systematic it is," Bintu said in a statement. "The spatial organisation in the nose is preserved and transformed in a very precise way in the brain."
This discovery was possible thanks to technological advances (specifically, a new 'spatial transcriptomics' technology called Multiplexed Error-Robust Fluorescent In Situ Hybridisation, developed at Harvard), Bintu and colleagues explain in their paper. In earlier studies, researchers had only been able to look at a handful of olfactory receptors at a time, so had been unable to generate large-scale maps.
These two studies show that, for mice at least, processing smells involves the use of spatial maps. Further work will now be needed to investigate whether we use a similar system. This type of work, which Bintu thinks could be done on post-mortem samples of human olfactory brain tissue from donors, could help not only with elucidating how we smell our world, but potentially with treatments for anosmia (an inability to smell), which can have all kinds of harmful impacts.
Read the paper in full:
Brann, D. H., Tatsuya Tsukahara, Tau, C., Kalloor, D., Lubash, R., Kannan, L. T., Klimpert, N., Mihaly Kollo, Martín Escamilla-Del-Arenal, Bogdan Bintu, Schaefer, A., Fleischmann, A., Bozza, T., & Datta, S. R. (2026). A spatial code governs olfactory receptor choice and aligns sensory maps in the nose and brain. Cell, 0(0). https://doi.org/10.1016/j.cell.2026.03.051
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