Sniffing new: Research into smell

The Breaking Science team discussed new research that might help our understanding of how we smell:

Kat Arney: They do say a rose by any other name would smell as sweet, but what does make us think that a rose smells nice but my feet smell bad? My feet don’t smell that bad. But until now scientists have known relatively little about how the smelly molecules, known as odorant molecules, are recognised by the receptors in our noses. But new research by Harumi Saito published in the journal Science Signalling this week could shed some light on this mystery.

Chris Smith: So come on then, tell us why does a rose to me smell like a rose and your feet smell, well let’s not go there.

Kat Arney: Well our sense of smell is an amazing thing and our noses have hundreds of olfactory receptors, each of which can pick up a different smelly molecule and this then sends a signal into the brain which gets interpreted as a smell. But we only know around about 50 of these smelly molecules and that somewhat limits our understanding of the whole system.

Chris Smith: So what are the researchers actually doing in this study to try and home in on what’s going on?

Kat Arney: Well they used a technique called high throughput screening which allowed them to carry out many, many experiments in a short time, and this allowed them to test 93 different odorants, these are the smelly molecules, against a panel of 464 different olfactory receptors, and they picked up 52 specific odorants that activate mouse receptors and the screen pulled out 10 new odorants that activate human receptors.

Jupiterimages
Smelling a flower.

So this has, you know, made a big increase on what we know about the number of specific molecules that interact with the smell receptors. And the scientists used the knowledge from their screen to then develop a computer model that can help to predict what kind of odorant molecules might fit with different olfactory receptors.

Now it’s probably possible to look at a whole range of smelly chemicals and try and predict which olfactory receptors they might bind to. So this is basically going to speed up the process of research in this area so scientists will have better ideas of which routes to follow rather than just taking shots in the dark.

Chris Smith: It’s interesting because before Christmas I spoke with a perfumer who makes smells for a living, nice smells, and he had the chemical equivalent of synaesthesia, he could imagine a smell and see the molecule in his mind’s eye that would smell like that, so I guess he’d be very interested in a function or a model like that.

Kat Arney: Absolutely. Fascinating.

Listen to the whole programme, originally broadcast on BBC Radio Five Live, February 2009