You meet somebody new and you feel it right away -- that vibe, that gut feeling, that certain je ne sais quoi. You're turned on. Or you're turned off. You instantly love him. Or you instantly hate her. But why? Why do some people give you an immediate sense of ease and well-being while others, for no logical reason, make you testy and suspicious and even repulsed?
Just possibly: pheromones. These chemical messengers that animals use to silently communicate have long stood as the scientific foundation for the fabled sixth sense. Now a team of researchers, by examining the neural wiring of mice, has shown how those chemical messages get processed. The results were reported in the April 16 issue of Cell.
In a mouse's head, there's a main olfactory system and an accessory olfactory system. The main system is wired to recognize individual molecules, to detect and distinguish odors -- cheese, for example. The wiring is more complex in the accessory system because it has to recognize complex blends of molecules: That's where the pheromones come in. "Pheromones are a collection of chemical stimuli that allow animals to signal dominance, or if a female is in heat, or aggression between males," explains Dr. Peter Mombaerts, an assistant professor at Rockefeller University and a member of the research team.
Mombaerts and colleagues manipulated the neural wiring in mice to see how they process pheromones. In a mouse's brain, neurons carry pheromonal information to the accessory olfactory bulb for processing in a structure called the vomeronasal organ (VNO). When the VNO is removed from mice, they undergo profound changes in mating behavior. If the VNO is removed from a sexually active mouse, for instance, the mouse becomes sexually dysfunctional and won't mate. In other words: Without those pheromone receptors, a mouse can't get laid.
But does any of this apply to humans -- our noses, our sex lives? According to Mombaerts, very little research has been done to study the effect of pheromones in humans. So what about those love potions sold on the market as pheromone fragrances -- are they genuine aphrodisiacs? "The term 'pheromone' is used very loosely. It's cocktail party conversation," Mombaerts says. "They [pheromone scents] may make you feel more attractive. It may work on your emotions. And so it may look like a pheromone effect. But that doesn't mean it actually works like a chemical pheromone."
Maybe it's just the placebo effect -- your pheromone fragrance makes you believe you're more charming and alluring, so you become more charming and alluring. You splash on a little Lure, for instance, and wait for Mr. or Ms. Right to drift over like a hound dog on the trail of your captivating scent. Meanwhile, your natural pheromones keep on wafting through the air, sending a chemical broadcast of the real you.
Dr. David Moran, co-author of "Love Scents," has said, "We're chemically communicating with other people all the time, even though we're not consciously aware that we're doing so." So, when in doubt, follow your nose.