Morgan L. Gustison - US grants

PROJECT SUMMARY Vocal communication is a fundamental behavior that humans and many other mammals use to cultivate social attachments. These social attachments are needed to protect against perceived loneliness, which is associated with an increased risk of mental disorders and physical disease. The long term goal of this research proposal is to uncover the unique role of vocal communication in building and maintaining social attachments, and to identify the neural circuits that link vocalization to bonding. Our laboratory has used whole-brain imaging of immediate- early gene (IEG) activity to map the neural systems active during pair-bonding in the monogamous prairie vole. This research implicates the medial prefrontal cortex (prelimbic, infralimbic, and anterior cingulate areas) as a key hub within the pair-bonding network. My work also shows that prairie voles are incredibly vocal throughout pair-bonding, with vocalization associated with affiliative interactions like courtship and proximity maintenance. We also find that vocalization rates are correlated with prefrontal IEG expression during bond formation. The proposed experiments will test the central hypothesis that prefrontal cortical regions modulate vocalizations that promote pair-bonding. The goal of the K99 phase research is to develop a foundational understanding of how vocal communication is involved in the pair-bonding process. In Aim 1, I will determine how inhibition of vocal production impacts affiliative interactions and whole-brain IEG induction during bond formation and maintenance. In the process, I will learn the systems neuroscience methods of iDISCO, light-sheet microscopy, and related analysis pipelines. In Aim 2a, I will map the prairie vole vocal circuit using trans-synaptic tracing and whole-brain imaging to determine where vocalization and bonding circuits overlap. This will deepen my training with whole- brain imaging and mammalian neuroanatomy, as well as train me in the viral mapping of neural circuits. To advance my managerial skills, my K99 training will also include formal, targeted training in leadership, project management, and mentorship, overseen by a diverse advisory committee. In the R00 phase, my research will test whether prefrontal regions promote vocalization during pair-bonding. In Aim 2b, I will map afferent and efferent projections of prefrontal regions to identify anatomical connections between the vocal and bonding circuits. In Aim 3, I will manipulate the anterior cingulate cortex and its descending projections to examine its influences on vocalization, bond formation, and bond maintenance. This research will provide insight on the neural substrates that link vocal behavior to social attachment. The training will allow me to build on my unique ethological background in animal vocalization with the modern tools of behavioral and systems neuroscience. The combined elements of this research proposal will lay a foundation for an independent career investigating the neural mechanisms through which communication supports healthy social connection.