What keeps love alive? Scientists discover ‘chemical imprint of desire’

BOULDER, Colo. — Experts have uncovered a biological signature of desire that causes us to lust over certain people more than others. Study authors observed that this imprint fades if there is no contact with the person for a while and that time can indeed heal heartbreak.

“As humans, our entire social world is basically defined by different degrees of selective desire to interact with different people, whether it’s your romantic partner or your close friends,” says Associate Professor Zoe Donaldson from the University of Colorado Boulder, in a media release. “This research suggests that certain people leave a unique chemical imprint on our brain that drives us to maintain these bonds over time.”

The study utilized neuroimaging technology on prairie voles, chosen for their propensity to form monogamous pair bonds, a trait shared by only three to five percent of mammals. In scenarios where a vole attempted to reach its partner in another room, researchers noticed that dopamine levels in the brain spiked, illuminating the sensor.

woman hugging man
Researchers say some people create a distinctive chemical mark in our brains that drives us to maintain connections over time. (Credit: Photo by Tim Mossholder On Unsplash)

Researchers describe the reunion as lighting up “like a rave,” with continued activity as the voles snuggled and sniffed each other. However, when faced with a stranger, the sensor dimmed significantly.

“This suggests that not only is dopamine really important for motivating us to seek out our partner, but there’s actually more dopamine coursing through our reward center when we are with our partner than when we are with a stranger,” explains study first author and graduate student Anne Pierce.

Interestingly, after a four-week separation, equivalent to an eternity in the rodent world, the dopamine surge nearly vanished upon reunion.

“We think of this as sort of a reset within the brain that allows the animal to now go on and potentially form a new bond,” Dr. Donaldson concludes.

“The hope is that by understanding what healthy bonds look like within the brain, we can begin to identify new therapies to help the many people with mental illnesses that affect their social world.”

The study is published in the journal Current Biology.

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South West News Service writer Isobel Williams contributed to this report.