Oxytocin is famously known as the “love drug” because it’s associated with the intimate bonds between lovers and family members. Scientists know it’s a neuropeptide that’s secreted into a person’s bloodstream from a gland at the base of the brain during moments of physical intimacy, but how exactly it affects our behavior — and our relationships with others — is unknown.
On Thursday, Stanford University scientists came a step closer to figuring it out. In a study published Thursday in Science, they revealed that as bursts of oxytocin coincide with positive social interactions, our brains are overwhelmed with a feeling of reward.
In an interview with Inverse, study co-author Dr. Robert Malenka said his team’s discoveries about oxytocin are especially timely. “At a time when there is enormous tension between individuals and societies with different worldviews, what is more important than understanding what allows us to feel good about each other?”
In their study, they came to an understanding of where oxytocin works in the brain, which led them to understand how it makes social interaction feel so good. “The findings of this paper suggest that one factor contributing to social behavior deficits may be abnormal modulation of the brain’s reward circuitry by oxytocin,” says Malenka.
With his team, Malenka, the co-director of the Stanford Institute for Neuro-Innovation and Translational Neurosciences, found that positive social interactions cause neurons to release oxytocin into the brain’s ventral tegmental area (VTA) — a region rich with dopamine and serotonin receptors, which are established parts of the brain’s reward system. The flood of oxytocin into the VTA after a social experience is what they think leads us to experience those interactions as positive and rewarding moments.
In experiments with adult male mice, they used a virus to knock out the mouse VTA’s oxytocin-releasing neurons so they could artificially manipulate the amount of oxytocin they released, in hopes of discovering what happened to mouse friendships when the hormone couldn’t do its job. After each mouse went through manipulations to either inhibit or excite the oxytocin-producing neurons, it was introduced to a younger juvenile mouse.
The scientists discovered that when oxytocin neuron activity was increased in the VTA, the subject mouse “spent more time hanging out with its younger buddy.” When those…