By Nicolle Charbonneau
HealthSCOUT Reporter

Whether a pheromone-scented perfume will help you spot a mate from 100 feet away is still a matter of debate, but a team of scientists has made what one expert is calling a "pivotal" discovery in pheromone research.

A pheromone is an organism's chemical equivalent of dropping a handkerchief, but scientists didn't know whether humans are chemically capable of picking that hanky up -- until now.

For the first time, researchers have identified a candidate that could be the pheromone receptor gene in humans. The gene -- called V1RL1 -- appears to be functional, setting it apart from several non-functional "pseudogenes" that the pheromone researchers have discovered over the years. Pseudogenes are not capable of producing a fully functional protein.

"It opens new avenues of research for the future," says pheromone expert Charles Wysocki, based at the Monell Chemical Senses Center in Philadelphia.

It's certainly enough to excite senior author Dr. Peter Mombaerts, the head of the Laboratory of Developmental Biology and Neurogenetics at Rockefeller University in New York. His team found the gene after searching for human genes that resembled the rat equivalent of the V1R receptor gene sequences.

They then screened several types of human tissues and found that V1RL1 was always evident in olfactory tissue. Their findings appear in the September issue of Nature Genetics.

Little data on human response

Pheromones are odorous substances secreted by various insects and animals. In subtle and not-so-subtle ways they can attract other animals or act as a social communicator or sexual stimulant. For example, certain male moths can smell -- and will seek out -- a female in heat from miles away, while female pigs will take a specific mating posture if exposed to a male pheromone while in heat.

But in humans, there has been little data showing that humans respond to pheromones. The most well known evidence describes how groups of human females living in groups, such as women living in college dormitories, tend to develop synchronized menstrual cycles.

Generally, pheromones are sensed using the vomeronasal organ (VNO), a structure inside the nose. In some animals, it's relatively large, but in humans, the millimeters-long groove is inactive. Some people don't even have one. That, says neuroscientist Charles Wysocki, may suggest that humans detect pheromones through the olfactory cells lining our nose, where the researchers have found the active V1RL1 gene.

"The receptor cells within the human VNO degenerate at anywhere between 17 and 19 weeks of gestation," says Wysocki. "There are some reports that suggest that on occasion, you can find these things in a newborn. But in adults, there's very little solid proof that there's any connection between the VNO and the part of the brain that would normally receive its input."

Less complex species, such as rodents and insects, are more dependent on pheromones, says Mombaerts. However, humans can rely on vision, auditory cues and of course, our more advanced mental functions. "Our behavior is a lot more sophisticated than that of a mouse," says Mombaerts.

But while it remains speculative, pheromones could have clinical uses, says Mombaerts. "If this receptor is involved in sexual arousal, for instance, you could use it to enhance the quality of sexual activities," he says. "It could lead to hormonal changes. You could interfere with the ovulatory cycle and influence the timing of ovulation during fertility treatments and diminish the effects of premenstrual syndrome."

But researchers don't know exactly what this gene does. "It's going to take a couple of years, because we have to find first what activates or blocks the receptor," says Mombaerts. And there may be other active genes that the researchers have yet to find. "The relationship may be trickier to spot. Certainly, the Human Genome Sequence information will be extraordinarily useful."

What To Do: You can find out more about pheromones from MSN Encarta, Micscape Magazine or the New York State Agricultural Experiment Station.