Study Reveals How Mice Can Quickly Identify Odors

Findings may improve understanding of how smells are processed and speed up computing by artificial intelligence tools

NEW YORK, April 14, 2026 /PRNewswire/ -- Mice make use of rapid nerve cell interactions in the brain's smell center to distinguish one odor from another, a new study shows. Both mice and humans can rapidly identify odors, researchers say, in a small fraction of a second.

Led by researchers at NYU Langone Health, the study shows that the key steps involved in identifying smells happen in the mouse olfactory bulb, a part of the brain located behind the nose. The function was previously thought to occur in the cerebral cortex, a larger part of the brain known for its role in perception, awareness, and thought.

Publishing in the journal Nature Neuroscience online April 14, the study shows that a subset of nerve signals activated first and within milliseconds, when a mouse just begins to take a sniff, determine which odor is identified. The entire sniff cycle in mice can last between a quarter and a half second; while in humans, the sniff cycle is longer and takes between one to three seconds (one second is 1,000 milliseconds.)

The findings centered on the processing of signals produced by millions of olfactory sensory neurons, cells in the mouse nose that are linked to olfactory bulb glomeruli (clusters of nerve endings.) These are in turn connected to batches of mitral and tufted cells (MTCs).

The study authors found that the olfactory bulb glomeruli-MTC signals triggered within the first 50 milliseconds of the sniff cycle determined the type of odor that tested mice perceived. In the process of rapid neural computations for odor sensing that the researchers have termed "temporal filtering," transmission of the first sets of activated olfactory nerve signals both determine the odor being smelled and block out later signals.

Specifically, the team found that the same pattern of linked glomeruli-MTC signals became active first for the same smell regardless of concentration of that odor. Once this pattern was set, activation by background odors of other sets of glomeruli blocked following nerve signals from passing along. Together, this enabled transmission of only the first set of signals belonging to the first identified smell.

"Our findings call into question a fundamental understanding about mammalian sensory processing, which is that these brain computations mostly occur in the cortex," said study co-senior investigator Dmitry Rinberg, PhD. "The work also demonstrates for the first time how mice, but possibly humans as well, use temporal filtering to distinguish between odors." Dr. Rinberg is a professor of neuroscience at NYU Grossman School of Medicine.

"This research is key to understanding how our sense of smell works but also how our complex neural networks are connected, and possibly how other complex biological and computational systems work," said study co-senior investigator Shy Shoham, PhD.

Dr. Shoham, director of the Tech4Health Institute at NYU Langone Health and a professor in the neuroscience and ophthalmology departments at NYU Grossman School of Medicine, said the team's research raises fundamental questions about the role of the cortex in processing sensory information, noting that recent advances in understanding vision similarly showed that the neural cues in the retina help tell objects apart, before any signals ever reach the cortex.

Temporal filtering, he noted, could also have application to artificial intelligence tools, if used to speed up processing of large amounts of sensory information.

Rinberg said the team next plans to examine how temporal filtering patterns in the olfactory system help distinguish between similar smells, such as citrus (lemon and orange), as well as distinguish among other sweet smells, such as those of berries or stone fruit.

The team's latest analysis was made possible by precision optogenetics, a technique that allows researchers to specifically activate or shut down neurons using pulses of light, and to determine which individual or close-knit neurons are electrically firing when exposed to different smells.

Study lead investigator Mursel Karadas, PhD, led development of the new circuit-mapping microscope used in the study. The technique allowed researchers to stimulate and track individual nerve signals in the thin, outermost layers of the olfactory bulb.

Funding support for this study was provided by National Institutes of Health grants U19NS107464, U19NS112953, and R01DC022320.

Other NYU Langone researchers involved in the study are co-investigators Jonathan Gill and Sebastian Ceballo. 

About NYU Langone Health

NYU Langone Health is a fully integrated health system that consistently achieves the best patient outcomes through a rigorous focus on quality that has resulted in some of the lowest mortality rates in the nation. Vizient Inc. has ranked NYU Langone No. 1 out of 118 comprehensive academic medical centers across the nation for four years in a row, and U.S. News & World Report recently ranked four of its clinical specialties No. 1 in the nation. NYU Langone offers a comprehensive range of medical services with one high standard of care across seven inpatient locations, its Perlmutter Cancer Center, and more than 320 outpatient locations in the New York area and Florida. The system also includes two tuition-free medical schools, in Manhattan and on Long Island, and a vast research enterprise.

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STUDY LINK
https://doi.org/10.1038/s41593-026-02250-y

STUDY DOI
10.1038/s41593-026-02250-y

SOURCE NYU Langone Health System