Neuropeptides are known to regulate social behaviors in representative species from all vertebrate classes. Species differences in behavior, however, have made development of clear mechanistic models difficult. This project investigates the complexity of behavioral mechanisms using a combination of field experiments and computational models. Field studies address important emerging questions on neuropeptide modulation of female affiliative behaviors. Synthetic experiments with agent-based models allow exploration of conditions impractical or impossible in empirical tests. The models are expected to propose new mechanisms for neuropeptide control of behavior. This project thus implements a tight experiment-model-experiment loop and develops a new paradigm for a systems biology approach to understanding social behavior. Neuropeptides can alter a variety of vertebrate social behaviors, including parental, aggressive, and reproductive behaviors. Specifically, this project will determine the effects of vasotocin on female phonotaxis in gray treefrogs and subsequently a computational model for phonotaxis that can make predictions as to how neuropeptides influence social behavior will be developed. This model will then be tested under natural conditions for verification. Results from these studies will significantly advance our understanding of the effect of neuropeptides on female behavioral plasticity. This project also includes a significant training component, with involvement of an undergraduate field biology class (populated with 30% under-represented minorities) and training of a post-doctoral fellow and graduate student in a unique inter-disciplinary environment. In addition, a new course on modeling approaches to behavioral sciences will be developed.
Intellectual merit: The social behaviors of animals can have significant consequences for the fitness of individual organisms and can profoundly influence evolutionary processes. Such behaviors -- with complex give-and-take between individuals -- appear to be some of the least amenable to reductionist approaches. Nonetheless, across vertebrate classes, conserved mechanisms at the molecular and cellular level support the presence of a "social brain," and indicate an important modulatory role for neurohypophysial peptides. In this project, we determined the effects of the neurohypophysial peptide arginine vasotocin on decision making in female amphibians and examined how conspecific male behaviors alter decision making. We have demonstrated complex interactions between multiple internal factors (e.g., gonadal steroid hormones, neurosteroids, energy reserves) and external factors (e.g., temperature, behavioral displays) in males and females. Understanding how changes in behavior of an individual can influence group dynamics is an important open question. In this project, we also developed an agent-based model of social behaviors that includes both male and female agents. Using the model, we showed significant differences in outcomes for individuals, depending upon decision making strategies and spatial structure of the environment. This led to new hypotheses about female decisions and behavioral plasticity in social contexts. Broader impacts: This grant contributed to the training of 2 post-doctoral fellows, 5 graduate students, and 11 undergraduates (including 2 who participated in a research-intensive summer course at Notre Dame's field station). It also led to the development of a spatial agent-based modeling environment that, in addition to research use, has been successfully employed in classroom settings (e.g., in a novel course at Tufts entitled "Artificial Agents and Autonomy.")
