Office of Research

Our research is focused on the structure and function of social behavior circuitry in the brain. Of particular interest are variations in structure and function that produce individual, sex, species and seasonal differences in behavior. Much of the behavioral diversity that we observe is produced by variation in gene expression rather than by large-scale reorganizations of social circuitry or major differences in anatomy. In fact, the core components of the brain's "social behavior network" are strikingly similar across vertebrate groups. Most of our work is conducted in socially diverse species of songbirds, including estrildid finches and emberizid sparrows. The estrildid finch family offers a unique ability to determine how neural and motivational processes have evolved in relation to sociality since species from this family display large variation in group sizes but are matched in other aspects of behavior and ecology.

Our work has focused on the nonapeptides vasotocin and mesotocin, which are homologues of the mammalian neuropeptides vasopressin and oxytocin. We have identified anatomical and functional properties of nonapeptide circuits that closely match individual, sex, and species differences in behavior. We have also manipulated nonapeptide systems and shown that we can influence an individual’s choice of group size, independent of that individual’s decision to be social. Other studies in our lab have demonstrated that these nonapeptides are important modulators of additional behaviors such as aggression, pair bonding, and anxiety-like behavior.

In addition to vasotocin and mesotocin, we have examined other neuropeptides and enzymes, including tyrosine hydroxylase, aromatase, corticotropin releasing hormone and vasoactive intestinal polypeptide (VIP), all of which appear to be relevant to individual, species and seasonal differences in social structure.

Of these, the neuromodulator VIP is currently a focus of ongoing lab studies since VIP cells, fibers and receptors are found in virtually every brain region that is important for social behavior. However, few studies have examined the behavioral functions of this peptide outside of its role as the main regulator of prolactin secretion from the pituitary. We are currently investigating whether VIP circuits may be variably important for grouping behavior, aggression, pair bonding, social anxiety and parental care in the gregarious zebra finch under support from the National Institutes of Health.