Have you ever felt an instantaneous connection with someone you just met? New research has suggested that there may be a biological reason for that flash of compatibility. Reporting in Molecular Psychiatry, scientists used a mouse model to show that in a region of the brain that's involved in mood and motivation, there's an enzyme that strongly influences which mice interact with each other socially. The work determined that mice with genetically similar versions of this enzyme prefer to hang out together.
The study authors suggested that there may be many biomarkers that can tell us more about social preferences. This work may also give us insight into conditions that have been associated with social withdraw, such as autism or schizophrenia, and may eventually help researchers find ways to improve those conditions.
"Imagine the possibilities of truly understanding the factors behind human compatibility," said study leader Michy Kelly, Ph.D., Associate Professor of Anatomy and Neurobiology at the University of Maryland School of Medicine. "You could better match relationships to reduce heartache and divorce rates, or better match patients and doctors to advance the quality of healthcare, as studies have shown compatibility can improve health outcomes."
Many years ago, Kelly's work suggested that mice that lacked a protein called PDE11 were socially withdrawn. In healthy mice the PED11 protein was found to be expressed in a part of the hippocampus that's known to be damaged in a mouse model of schizophrenia.
Years later, during Kelly's work involving the social behavior of mice, Kelly's team determined that mice lacking PDE11 preferred to socialize with other mice that lacked PDE11, while normal, wild-type mice had a preference for other mice that were genetically similar to themselves. When researchers tested different genetic variants of the PDE11 enzyme, they found that it only took a small change in the sequence for mice to prefer to be with other mice that had PDE11 sequences that were similar to theirs; mice wanted to socialize with mice that had the same PDE11 variant.
The scientists are still working to determine how the mice can detect the PDE11 variant, and select the one that matches their own.
"So, what is it that the mice are sensing that determines their friend preferences? We eliminated smell and body movements as contributing factors, but we still have some other ideas to test," said Kelly.