Molecular Neurobiology of Social Bonding

Many psychiatric illnesses, including autism spectrum disorders (ASD), schizophrenia, and depression, are characterized by impaired social cognition and a compromised ability to form social relationships. Although drugs are currently available to treat other symptoms of these disorders, none specifically target the social deficits. In order to develop pharmacotherapies to enhance social functioning, particularly for ASD where social impairment is a core symptom, we must first understand the basic neurobiology underlying complex social behaviors. The socially monogamous prairie vole (Microtus ochrogaster) has been a remarkably useful animal model for exploring the neural systems regulating complex social behaviors, including social bonding. Prairie voles form enduring social bonds between mated partners, or pair bonds, and display a biparental familial structure that is arguably very similar to that of humans. Here we discuss the neural systems underlying social bonding in prairie voles, including the neuropeptides oxytocin and vasopressin, opioids, dopaminergic reward and reinforcement, and stress-related circuitry, as well as the susceptibility of social functioning to early life experiences. We highlight some of the remarkable parallels that have been discovered in humans, and discuss how research in prairie voles has already led to novel therapies to enhance social functioning in ASD.