Neuroscientists from the University of Colorado Boulder have revealed the biological signals of desire, explaining why certain bonds like love and loss are more profound than others

Published in the journal Current Biology on January 12, the research focuses on prairie voles, understanding the intricate role of dopamine in maintaining long-term relationships similar to human bonds.

Prairie voles are among the rare 3% to 5% of mammals that form monogamous pair bonds, offering a unique opportunity to study the neurochemical basis of intimate relationships.

Love and loss: Forming long-term partnerships

Like humans, prairie voles engage in long-term partnerships, share a home, raise offspring, and experience a sense of grief when separated from their partners.

The research, led by senior author Zoe Donaldson, associate professor of behavioural neuroscience at CU Boulder, utilises state-of-the-art neuroimaging technology to look into the real-time brain activity of voles during attempts to reunite with their partners.

The findings reveal that dopamine, a neurotransmitter associated with pleasure and reward, plays a pivotal role in sustaining the bonds of love.

Donaldson explains, “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. This research suggests that certain people leave a unique chemical imprint on our brain that drives us to maintain these bonds over time.”

“certain people leave a unique chemical imprint on our brain”

Interacting with partners

The researchers monitored the voles as they navigated obstacles to reach their partners, with a fibre-optic sensor tracking dopamine activity in the nucleus accumbens, a region responsible for motivating individuals to seek rewarding experiences.

The results showed that dopamine surges, lighting up the voles’ brains like a glow stick during interactions with their life partners.

Anne Pierce, the study’s first author, explains, “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.”

How the brain reacts to reuniting with someone you love

In an experiment simulating separation, the voles were kept apart for four weeks, a significant duration in their lives. Upon reuniting, while the voles remembered each other, their signature dopamine surge had diminished significantly. The researchers interpret this as a neural reset, allowing the animals to form new bonds.

The implications for humans are deep, especially for those suffering from heartbreak or loss. The study hints at an inherent mechanism within the brain to protect individuals from prolonged, unrequited love.

How will these results translate to humans?

The authors acknowledge the need for further research to determine how well these results translate to humans. They believe the findings could offer insights into mental health conditions affecting social relationships.

Zoe Donaldson expresses hope for the future, stating, “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.”

This research provides a glimpse into the neuroscience of love and holds promise for potential therapeutic interventions to assist those struggling with forming or overcoming close relationships. As the field progresses, scientists aim to unlock the mysteries of the human brain, offering new perspectives on emotional bonds and avenues for mental health support.