Love has inspired timeless songs and sonnets — not to mention a few less-than-timeless romantic comedies. Now the chemistry of love is the subject of the latest episode of the American Chemical Society’s Reactions YouTube series (formerly Bytesize Science). Just in time for Valentine’s Day, the video is available at http://youtu.be/bp7Ydv5wAPk.

The video explains how feel-good neurotransmitters like dopamine and oxytocin fuel lifelong pair bonds in prairie voles, which — along with humans — are the mammalian kingdom’s leading monogamists. “If you block oxytocin receptors, you can totally cut off that pair-bonding response,” explains Abigail Marsh, Ph.D., associate professor of psychology at Georgetown University. “People who excite romantic feelings in us also probably trigger increases in oxytocin, which results in an increase in dopamine, and then we find that person [to be] someone we want to stick with.” In the video, Marsh also explains that addictive drugs affect the brain in ways similar to love — which helps explain the painful, withdrawal-like symptoms of heartbreak.

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The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 161,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.