Humans, flies smell alike, neurobiologists find

March 26, 2007

The nose knows – whether it’s on a fruit fly or a human. And while it would seem that how a fruit fly judges odors should differ from how a human smells, new research from Rockefeller University finds that at the neurobiological level, the two organisms have more in common than one might expect.

While it is very easy to ask a person about an odor – how intense it is, what it is similar to – it is slightly harder with an insect. “It is not known in much detail how these insects respond behaviorally to odors,” says Andreas Keller, first author of the paper and a postdoc in the laboratory of Chemers Family Associate Professor Leslie Vosshall. Keller designed experiments to look at exactly how a single fly would behave when exposed to different odors. He and Vosshall found that both flies and humans judge odor intensity the same way, but differ in their judgment of quality.

In flies, as in humans, the olfactory system is composed of nerve cells, each of which expresses an odorant receptor. Each receptor recognizes a small set of odors and it is the combination of the nerves that respond to each odor that generates our, or the fruit fly’s, reaction to the smell. Each animal has a different number of these odorant receptors – there are 1,200 in mice, 400 in humans and 61 in fruit flies. Vosshall and Keller wanted to know how it is that humans and fruit flies can coexist and develop such very different numbers of odorant receptors.

“It is not well understood how the varying numbers of odorant receptors impact odor perception across the different species,” says Vosshall. “Our research found that while determining the intensity of an odor is conserved in humans and flies, odors that smell similar to a human do not necessarily smell similar to a fly.” There may be fundamental variations in the properties of the fly and human olfactory systems that cause the difference.

Vosshall and Keller also saw that the contribution of a specific odorant receptor could not be predicted based on its physiological function. When they genetically removed single odorant receptors from a fly they could not predict how that would change the fly’s behavior. “It may be that by removing just one receptor it changes the whole olfactory system and produces an entirely new odor precept,” says Vosshall. “Investigating how a fruit fly experiences odors can provide us with clues to our own subjective experiences of smell.”

Citation: Proceedings of the National Academy of Sciences Online: March 19, 2007

Source: Rockefeller University

Explore further: Researchers show that the mosquito smells, before it sees, a host

Related Stories

Microalgae produced on a commercial scale

June 18, 2015

Many products, including food supplements, cosmetics and biodiesel, are made from substances derived from microalgae. A fully automated pilot plant operated by Fraunhofer in Leuna is capable of producing microalgae on pilot ...

Insect mating behavior has lessons for drones

May 29, 2015

Male moths locate females by navigating along the latter's pheromone (odor) plume, often flying hundreds of meters to do so. Two strategies are involved to accomplish this: males must find the outer envelope of the pheromone ...

Do you have the time? Flies sure do

May 28, 2015

Flies might be smarter than you think. According to research reported in the Cell Press journal Current Biology on May 28, fruit flies know what time of day it is. What's more, the insects can learn to connect different scents ...

One simple molecule regulates sexual behavior in Drosophila

May 20, 2015

The common vinegar fly Drosophila melanogaster is a very well-studied animal. For decades, the fly has been used as a model organism in genetic research; its genome was fully sequenced in 2000. However, until now researchers ...

Recommended for you

Magnetism at nanoscale

August 3, 2015

As the demand grows for ever smaller, smarter electronics, so does the demand for understanding materials' behavior at ever smaller scales. Physicists at the U.S. Department of Energy's Ames Laboratory are building a unique ...

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.