The ability to form long-term pair bonds is exhibited by only a small percentage of mammals and is, therefore, the exception rather than the rule. Research by Emory University’s Larry Young demonstrated for the first time that differences in complex social behavior are the result of genetic variation.
Young and his colleagues at the Yerkes National Primate Cente traced the monogamous and polygamous behaviors of species of voles to differences in the structure of the gene that codes for brain cell receptors for vasopressin and oxytocin—hormones released when males and females meet and mate. “We found that, in monogamous species, receptors for these hormones are found in higher numbers in the reward centers of the brain, the same brain regions involved addiction,” Young said.
In honor of this pioneering work in brain research, Young was named the recipient of the 2008 Golden Brain Award by the Berkeley, California-based Minerva Foundation. The award was presented to Young in a private ceremony during the 38th annual meeting of the Society for Neuroscience, which was held in Washington, DC.
“Larry Young has conducted excellent work using animal models that is now the basis of human studies into the molecular mechanisms behind behavior, emotion and love,” said the late Elwin Marg, professor emeritus of vision sciences at the University of California Berkeley and co-founder of the Minerva Foundation.
Thanks to Young’s work, researchers are beginning to shed some light on the evolution and maintenance of human trust, cooperation and social behavior by looking at the vasopressin/oxytocin peptide family and the distribution of their respective receptors in the human brain. Recent work by Swedish researchers, for example, showed that variation in the human vasopressin gene AVPR1A predicts relationship quality, such as whether a person is likely to ever get married.
In voles, social behaviors correspond to ecological niches, with prairie voles being the monogamous species and meadow and mountain voles being the polygamous ones. “We’ve shown that you can take the prairie vole form of the gene and put it into the reward area of the brain of a meadow vole and it will be able to form social bonds,” Young said. He was also able to take the receptor gene from the monogamous prairie vole and put it into mice, making them more social.
Young continues to refine his work in voles, while human studies into this fascinating research area are just getting started. Already, research has shown that oxytocin enhances trust and the ability to infer the emotions in humans. “These hormones are likely responsible for tuning us into the social world,” he explained.
Young and his colleagues theorize that human studies on the roles of vasopressin and oxytocin could one day be used to enhance marital therapies, or perhaps even lead to a treatment for disorders of social behavior, including autism. “It’s possible,” Young said.