Scientists create detailed map of odor receptors

May 12, 2026

Scientists create detailed map of odor receptors

Sensory systems are organized in space. Receptors at different positions detect distinct signals and send them to the brain. Scientists in recent years have created detailed maps of receptors for the senses of touch, sight, and sound. But the sense of smell has been more difficult to map, in part because smell is so complex. The inner lining of the human nose houses about 500 different types of odor receptors. A mouse has more than 1,000 different types.

The sense of smell plays a key role in health. It helps you choose what to eat or avoid, and it can warn you of dangers like fires or gas leaks. In many animals, smell is also essential for social interactions. Smell can play a role in recognizing infants, mating partners, or predators.

When you breathe in, odor molecules enter the nose and can trigger specialized sensory neurons, or nerve cells. Each of these neurons has only one type of odor receptor, which can latch onto specific odor molecules. These sensory neurons send signals to a brain structure called the olfactory bulb.

Scientists have long thought that odor-detecting neurons have a loose spatial organization within the nose. In this view, each of several broad zones houses a seemingly random assortment of odor-detecting receptors.

Two independent teams of researchers decided to take a closer look. One team was led by Drs. Catherine Dulac and Xiaowei Zhuang of Harvard University, the other by Dr. Sandeep Robert Datta of Harvard Medical School. They used advanced microscopy and genetic techniques to characterize millions of smell-related neurons in hundreds of mice. Results of both studies appeared in Cell on April 28, 2026.

The researchers began by using a method called single-cell RNA sequencing. This shows which genes are turned on, or expressed, in individual cells. This type of analysis involved removing cells from surrounding tissues. To learn how the neurons were organized in three-dimensional space, the scientists turned to a method called spatial transcriptomics. This let both research teams pinpoint the location and orientation of odor receptors in the nose.

Their analysis revealed a spatial pattern not recognized before. They found that neurons with similar types of receptors were arranged in tight horizontal stripes, from the top of the nose to the bottom. Further analyses by the Datta lab showed that during development, a molecule called retinoic acid plays a key role in determining receptor arrangement within the nose.

The researchers also found that their detailed receptor map aligned with the receptor map in the brain's olfactory bulb. This sheds new light on how information travels from the nose to the brain.

The Dulac/Zhuang team also explored how mice recognize social odors, such as from male, female, and infant mice, as well as predators. They found distinct spatial domains of social odors in the nose and olfactory bulb. The team found differences in the map of infant odors between lactating mothers and virgin females. The scent of pups activated more odorant receptors and brain regions in mothers than in virgin female mice. "Mothers in all mammalian species, including humans, are known to be extraordinarily sensitive to the smell of infants, and our results uncover the neural substrates underlying this observation," Dulac says.

The scientists note that this type of olfactory map may one day offer insights for characterizing and treating conditions that affect the sense of smell. Certain respiratory infections, cancer treatments, or medications can cause temporary loss of smell. Smell can be permanently affected by older age, head injury, or certain chemicals.

"Smell has a really profound and pervasive effect on human health, so restoring it is not just for pleasure and safety but also for psychological well-being," Datta says. "Our results bring order to a system that was previously thought to lack order."

Related Links

• Complete wiring map of the insect brain
• Long COVID symptoms linked to inflammation
• Researchers create developmental map of mouse cochlea
• How the nose decodes complex odors
• Building an atlas of brain function in mice
• Problems with your smell or taste?
• Brain Research through Advancing Innovative Neurotechnologies® (BRAIN) Initiative
• Smell disorders
• How smell and taste change as you age

References

A spatial code governs olfactory receptor choice and aligns sensory maps in the nose and brain. Brann DH, Tsukahara T, Tau C, Kalloor D, Lubash R, Kannan LT, Klimpert N, Kollo M, Escamilla-Del-Arenal M, Bintu B, Schaefer A, Fleischmann A, Bozza T, Datta SR. Cell. 2026 Apr 28:S0092-8674(26)00387-9. doi: 10.1016/j.cell.2026.03.051. Online ahead of print. PMID: 42054991.

Spatial organization and detection of social odors in mouse primary olfactory system. Bintu B, Isogai Y, Jenie I, Zhuang X, Dulac C. Cell. 2026 Apr 28:S0092-8674(26)00389-2. doi: 10.1016/j.cell.2026.03.053. Online ahead of print. PMID: 42054995

Funding

Paper by Brann et al.: NIH's National Institute on Deafness and Other Communication Disorders (NIDCD); National Science Foundation; Tan-Yang Collective at Harvard.

Paper by Bintu et al.: NIH's National Institute of Mental Health (NIMH), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH Director's Office (OD); Howard Hughes Medical Institute.