In the same lab, older volunteers who claimed to still be intensely in love after two decades of marriage participated in the same experiment. The same brain areas lit up, showing that, at least in some lucky couples, that honeymoon feeling can last. But in these folks, other areas lit up, too -- those rich in oxytocin, the "cuddling" chemical that helps new mothers make milk and bond with their babies, is secreted by both sexes during orgasm, and that, in animals, has been linked to monogamy and long-term attachment.
It's way too soon - and hopefully, always will be - to say that brain scientists have translated all those warm and fuzzy feelings we call romantic love into a bunch of chemicals and electrical signals in the brain.
But they do have a plausible hypothesis: that dopamine plays a big role in the excitement of love, and oxytocin is key for the calmer experience of attachment. Granted, the data are preliminary. But the findings so far are provocative.
And it's conceivable that, as Emory University neurobiologist Larry J. Young pointed out in the journal Nature earlier this year, once scientists understand the chemistry of love, drugs to manipulate the process "may not be far away."
In fact, a study published this year in Biological Psychiatry supports that idea, showing that oxytocin may help human couples get along better. Swiss researchers gave 47 couples a nasal spray containing either oxytocin or a placebo. The couples then participated in a videotaped "conflict" discussion. Those that got oxytocin exhibited more positive and less negative behavior than those given the placebo. Oxytocin was also linked to lower secretion of cortisol, a stress hormone.
Emory's Young noted in the Nature paper that both Prozac, an antidepressant, and Viagra, an erection enhancer, appear to affect the oxytocin system, though it's not yet known whether such drugs affect relationships by changing brain chemistry.
