If I came across the phrase “smelled danger” in a manuscript, my cliché alarms would blare. But there may be some truth to the idea that fear has a distinct odor – other than sweat.
When an animal is threatened, a specific set of physiological responses occur to help the animal defend itself or escape. This is known as the fight of flight reaction. In addition, many organisms release chemicals known as alarm pheromones that are believed to warn other members of the community of the presence of danger.
Recently, a collection of nerve cells (the Grueneberg ganglion), located in mammalian noses, have been shown to detect alarm pheromones. Unfortunately, the pheromone molecules have not yet been identified, and nothing is known about their molecular receptors. The truly interesting stuff is yet to be discovered.
For more information see the New York Times Science Page or the Aug. 22, 2008 edition of Science. (I’ll add the exact reference to Science when that edition of the journal finds it way home from my husband’s laboratory.)