BRC-BIO: Neuroendocrinology of flying squirrel social behavior

Salisbury University, Salisbury MD

Investigators

Abstract

The southern flying squirrel is a common native species in the eastern half of the United States. These squirrels selectively nest with un-related individuals throughout the year. It has been assumed that these squirrels co-nest because when they huddle together, they can keep warm and save energy. However, research has shown that these squirrels continue to group in warm latitudes and during summer months. Instead, it appears that these squirrels form selective ‘friendships’ and choose specific squirrels to huddle in the nest with throughout the year. This project will examine how hormones and the brain affect this nesting behavior, using the flying squirrel as a model of friendship in non-kin. The aims of this research are to quantify the effects of specific hormones in the brain (oxytocin and vasopressin) on this behavior and to characterize how sensitivity to these hormones in the brain changes, including seasonaly, to facilitate co-nesting in flying squirrels. These data will help determine how the brain functions to support non-familial (i.e., ‘friendship-like’) relationships and social behaviors. This project supports engaging undergraduates in hands-on neuroscience research through paid research opportunities and a capstone project. Finally, though the flying squirrel is locally abundant, most Marylanders have never seen a flying squirrel nor are they aware that flying squirrels are living in the local forests. Through outreach at the local zoo, the research team will share the wonders of the flying squirrel with the public. Despite the body of work on the mechanisms of recognition, memory, and familial bonding, we lack understanding of the neural processes in selective, affiliative relationships. Therefore, this work will bridge this gap by studying the role of the nonapeptides, oxytocin and vasopressin, in the regulation of non-familial selective affiliation using the flying squirrel as a model. This project employs three strategies: First, the impacts of intranasal oxytocin or antagonist on communal nesting behavior will be examined. Second, fluorescent co-labeling of nonapeptide-expressing neurons and immediate early gene expression will be used to identify brain regions where the nonapeptides are released during co-nesting. Finally, the impact of season (i.e., photoperiod) on the presence and density of nonapeptide receptors will be determined, and examined in relation to co-nesting behaviors across the seasons. To understand the unifying principles of the evolution of sociality, robust, experimental data are needed from species with behaviors that range from asocial to gregarious. This work will fill a critical gap in this field by studying the neural mechanisms of sociality via long-term affiliative relationships. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.