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When the Cuddle Hormone Is a Home Wrecker

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


First off, this study on a molecule tied to social interaction was conducted in animals. So I’m supposed to turn on the siren and the flashing red light here to let you know that the headline you just read might not apply in humans. Still, the animals in question, prairie voles, are a special case, models of faithfulness that put humans to shame when it comes to the delicate topic of monogamy. Once hitched, the rodents stick with their mates for life—an example of moral pulchritude in the animal kingdom that many of us human sinners can never hope to emulate. It could easily become the state animal for whole regions of the U.S.

For just that alone, the implications of the experiment in question are particularly intriguing. The new research shows that oxytocin, the bonding hormone, is sometimes capable of turning the upstanding rodent into an anti-social lout, making the study results more compelling in many ways than if they were reported in errant humans. So the man-bites-dog headline stays.


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This all came up when Karen Bales, a professor at University of California, Davis, wanted to know what would happen if oxytocin gets administered for lengthy intervals, not the short-term dosing that has occurred in the multitude of previous vole studies that linked the hormone to monogamous behavior.

In their experiment, Bales and team gave either a low, medium or high dose through the nose to 29 voles, and a saline solution to 14 controls At first, the animals became all cuddly as in previous studies But after three weeks, an entire vole childhood (from weaning to sexual maturity), they started breaking bad. Males did not engage in the normal behavior of "pair bonding," that drives them to look for the girl of their dreams. And female voles' natural mothering instinct seemed to disappear: when placed nearby young pups that were not their own, they didn't dote, as they are wont to do. The cuddle hormone had turned the rodents into meanies.

Bales presented her work along with her graduate student Allison Perkeybile at the giant annual meeting of the Society of Neuroscience in New Orleans and the results are being published in the journal Biological Psychiatry. Just a vole study perhaps, but it might have some implications for use of the hormone in humans. Multiple clinical trials are under way to test oxytocin as a treatment for the social dysfunction that occurs in developmental disorders like autism and schizophrenia. Some physicians are already prescribing it off-label and it has taken on a cult status. Social commentator Naomi Wolfe, for one, called it "women's emotional superpower." And, of course, the buzz has fueled online sales.

The study showed one off-kilter effect that warrants caution for a parent that might want to try a little spritz up the nose of an autistic child. "I think the scariest thing to me was that the worst anti-social effects were at the lowest dose," Bale says. " And what's also scary is that if you take your kid to the doctor, you're going to want to start out at the lowest dose."

"I don't think we can count out oxytocin," she continues, "but we have to be very careful with the dosing." As always, more research is needed. Bales would like to know what would have happened if the animals had continued to receive the hormone as they matured. Until researchers come closer to an answer, though, it might be best to stay far away from the cuddle juice.

 

 

 

Image Source: Kathy West/University of California, Davis

 

 

Gary Stix, Scientific American's neuroscience and psychology editor, commissions, edits and reports on emerging advances and technologies that have propelled brain science to the forefront of the biological sciences. Developments chronicled in dozens of cover stories, feature articles and news stories, document groundbreaking neuroimaging techniques that reveal what happens in the brain while you are immersed in thought; the arrival of brain implants that alleviate mood disorders like depression; lab-made brains; psychological resilience; meditation; the intricacies of sleep; the new era for psychedelic drugs and artificial intelligence and growing insights leading to an understanding of our conscious selves. Before taking over the neuroscience beat, Stix, as Scientific American's special projects editor, oversaw the magazine's annual single-topic special issues, conceiving of and producing issues on Einstein, Darwin, climate change, nanotechnology and the nature of time. The issue he edited on time won a National Magazine Award. Besides mind and brain coverage, Stix has edited or written cover stories on Wall Street quants, building the world's tallest building, Olympic training methods, molecular electronics, what makes us human and the things you should and should not eat. Stix started a monthly column, Working Knowledge, that gave the reader a peek at the design and function of common technologies, from polygraph machines to Velcro. It eventually became the magazine's Graphic Science column. He also initiated a column on patents and intellectual property and another on the genesis of the ingenious ideas underlying new technologies in fields like electronics and biotechnology. Stix is the author with his wife, Miriam Lacob, of a technology primer called Who Gives a Gigabyte: A Survival Guide to the Technologically Perplexed (John Wiley & Sons, 1999).

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