Special Cells Intercept Irritating Smells

Does cutting an onion bring you to tears? Scientists do not understand why certain smells, like onion, ammonia, and paint thinner, are so irritating, but a new NIDCD-funded study has uncovered an unexpected role for specific cells in the front of the nasal cavity.

Weihong Lin, Ph.D., of the University of Colorado Denver School of Medicine and University of Maryland, Baltimore County, led the study which discovered that a particular cell, abundant near the entry of many animal noses, plays a crucial and previously unknown role in transmitting irritating and potentially dangerous odors. Dr. Lin and colleagues from both universities plus the Mount Sinai School of Medicine identified the role of this solitary chemosensory cell in transmitting irritating chemical odors in the noses of mice. Their study appears in the March issue of the Journal of Neurophysiology (available for a fee from the journal).

Prior to this work, scientists who study smell and taste thought that irritating odors directly stimulated the trigeminal nerve, which senses touch, temperature, and pain throughout the head region, including the delicate membranes that line the inside of the nose. The research team, under the guidance of Diego Restrepo, Ph.D., found that solitary chemosensory cells scattered in the epithelium inside the front of the nose respond to high levels of irritating odors and relay signals to trigeminal nerve fibers.

Read the NIDCD news release.

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