Can you smell something in the air?

I think I can safely assume that most everyone has heard of pheromones at one point or another. However, one thing I don't think most people realize is that the evidence for pheromonal activity in humans has been far from conclusive. For one thing, humans not only lack functional genes homologous to most pheromone receptors that have been discovered; we even seem to lack the organ that pheromone receptors are generally found in! Also, there is very little evidence for pheromonal effects: the only article I can recall having heard of before today is Stern & McClintock's Regulation of ovulation by human pheromones.

But all that may be about to change:

On that dream date, something really might be in the air. Results from a mouse study may bolster the evidence for human pheromones, the long-debated chemical signals thought to unconsciously sway our behaviour...

... Finding such receptors in the lining of the nose, rather the vomeronasal organ, is a more direct parallel with humans. Stephen Liberles and Linda Buck report their finding online this week in Nature (S. D. Liberles & L. B. Buck Nature doi:10.1038/nature05066; 2006)1. They isolated a group of receptors that can be triggered by at least one known mouse pheromone.

Genes encoding this family of receptors are also found in humans. "It's probably our best bet yet for functional pheromone genes in humans," says Timothy Holy, a neurobiologist at Washington University in St Louis, Missouri.

For their part, Liberles and Buck are cautious about labelling the mouse proteins as pheromone receptors. They have not yet carried out a key test to show that activating or eliminating the receptors alters a mouse's behaviour. But Buck says that her team is "intrigued by the possibility" of their being pheromone receptors, and is embarking on tests to find out.

Olfactory systems are one of the big areas of research in neuroscience right now. I'm honestly not sure why that is. But if Linda Buck--who won a Nobel Prize for her work on cloning and investigating the molecular mechanisms of olfactory receptors--is able to conclusively confirm the existence of pheromone receptors in humans, I think you're going to see an explosion of research in that area. Of course, I could be talking through my hat here.