A single gene inserted into the brain can change promiscuous male rodents into faithful, monogamous partners, scientists said on Wednesday.
It may not be quite that simple to rein in human philanderers - many genes as well as other factors are probably involved in relationships among people.
But researchers at the Yerkes National Primate Research Centre of Emory University and Atlanta's Centre for Behavioural Neuroscience (CBN) in the United States said their rodent results could help to explain the neurobiology of romantic love.
"Our study...provides evidence in a comparatively simple animal model, that changes in the activity of a single gene profoundly can change a fundamental social behaviour of animals within a species," said Larry Young a researcher at the university.
Gene transferred in virus
"It is intriguing to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships"
Researcher, Emory University
He and his colleagues, who reported their research in the science journal Nature, used a harmless virus to transfer the gene for a key hormone involved in sexual behaviour from monogamous prairie voles into the brains of their randy relatives, the meadow voles.
After the gene transfer, the previously promiscuous meadow voles had less of a roving eye and showed a distinct preference for their current partners.
Earlier research had shown that prairie voles, which form life-long partnerships, had higher levels of receptors for the hormone vasopressin in an area of the brain called the ventral
pallidum, than meadow voles.
Introducing the gene increased the natural levels of the receptor and enhanced the meadow voles' ability to form pair bonds.
Previous studies have also suggested that the receptors may play a role in disorders such as autism, and that brain pathways involved in romantic relationships also play a part in drug addiction.
"It is intriguing," said Young, "to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships."