Disentangling mechanisms of sociality and mating tactics

Public Award Abstract

Across vertebrates, males use a diversity of tactics to gain access to reproductive females, and these tactics may be associated with variation in sociability. For example, males that form highly selective pair bonds with one female might be less generally social whereas males that are highly social may express an alternative mating tactic, where they court and mate promiscuously with many females despite being bonded.

This project proposes that understanding new and distinct mating tactics that emerge in some males requires understanding the interaction of brain-behavior relationships that underlie high sociability (known as prosocial behavior) and selective social behavior that leads to pairbonding. By exploring brain-behavior relationships of these two social behaviors, the project aims to understand the neural sources for behaviors that can only be studied by indirectly exploring the neural sources of other behaviors within the social brain.

In this case, understanding male fidelity to a pairbonded partner requires understanding the neural basis of variation in sociability. This project explores the novel idea that some social behaviors are indirectly rooted in neural circuitry that serves a distinct but similar function. The aims of these studies represent a shift in thinking about the function of the social brain.

In doing so, we will train undergraduate students in advanced techniques in neuroscience, and formally train them to engage in science outreach with a population of underserved (mostly refugee) elementary school-aged children. Technical abstract

Sociality and mating systems are interdependent classes of behavior that govern distinct elements of reproductive decision-making. This project will disentangle the aggregated effects of general and selective prosocial behavior to study variation in alternative reproductive tactics. The hypothesis is high sociability creates opportunities for sexual infidelity via social access.

The lateral septum (LS) is highly networked and impacts both sociability and mating system. Focus is placed on prairie voles, a socially monogamous species where pairbonded males vary in sexual fidelity, in spite of maintaining strong pairbonds. A key prediction is that social promiscuity (i.e., non-specific social approach) is gated by the connections between the medial bed nucleus of the stria terminalis (BSTm) and the LS.

High sociability should create opportunities for animals to engage in extra-pair courtship and copulation independent of bond strength. The project will determine: [1] the role of BSTm-LS neuronal activity in regulating social monogamy using retro-Cre chemogenetic neural manipulations, [2] how vasopressin and GABA in the LS modulate social approach and sexual infidelity using pharmacological manipulation and visualizing neural activity, and [3] if LS neural activation via chemogenetics affects social approach and mating decisions in a complex social context.

This research will exploit the intersection between prosociality and monogamy to broaden understanding of social brain function by manipulating neuronal function in one domain of social behavior to observe the consequences in another (reproductive decision-making). The project will leverage a strong record of training URM students at all levels in advanced methods in neuroethology, and community engagement with underserved and marginalized K-12 aged children in a community classroom environment.

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.