Social interaction is a critical component for the formation and development of interpersonal relationships. In order to facilitate social interaction, humans have developed a specialized set of perceptual skills allowing for rapid assimilation of socially relevant information. These skills are often referred to collectively as social perception and in normal development the human brain forms specialized brain circuitry to accommodate these skills. Individual differences in social perception have a strong heritable component and therefore should be mediated by common genetic variation that impacts the structure and function of this specialized brain circuitry. However, contemporary genetic techniques focusing on the DNA sequence variation have been limited in explaining variability in complex social behavior. One potential solution to this problem is to expand the approach to consider other biological processes that impact the function of the gene without changing its sequence. These modifications are referred to as 'epigenetic' and are thought to play a critical role in healthy and disordered behavior. With support from the National Science Foundation, Drs. James Morris and Jessica Connelly of the University of Virginia are combining approaches from human neuroscience with molecular genetics to explore the role of epigenetic processes on neural circuitry supporting social perception. The project focuses on defining individual epigenetic variability along the oxytocin receptor gene. Oxytocin is a hormone that acts as a neurotransmitter in the mammalian brain and plays a critical role in social perception. Epigenetic modification of the oxytocin receptor gene influences its function and therefore should influence behaviors that are mediated by oxytocin. To test this hypothesis, subjects are assessed for epigenetic variability along the oxytocin receptor gene and then have their brains scanned while performing three common tasks that engage brain circuitry underlying social perception. The primary analysis focuses on the relationship between epigenetic variability and brain activity related to social perception. Secondary analyses consider how this relationship is related to complex behaviors such as empathy and stress reactivity.
This project establishes a new paradigm to understand how genetic variability can impact social behavior. To date, epigenetic modifications have been largely ignored when considering how genes may modulate brain activity as measured by modern neuroimaging techniques. The application of epigenetic techniques to neuroscientific investigations of social behavior will contribute to new models of personality and individual differences, and help explain vulnerability to psychiatric and developmental disorders that are defined by a wide range of individual differences. The project presents a unique opportunity for students wishing to cross-train in genetics and human neuroscience.
