CAREER: Oxytocin Modulation of Sound Processing

When a baby cries, parents respond quickly and know where their baby is immediately. However, how animals can find, or localize specific individuals, particularly those that are incredibly socially important like offspring or a partner is not well understood. A common hormone, oxytocin - that is involved in social bonds like with kids or partners – may tune a specific area of the brain to social sound information such as a baby’s cry. Dr. McCullagh’s lab will explore how oxytocin is involved in this area of the brain using a highly social animal called a prairie vole that forms bonds with their partner and shows parental care like humans. Dr. McCullagh’s project will have broad impacts on the community through a proposed course engaging students with neuroanatomical techniques at Oklahoma State University and a mobile interactive exhibit in partnership with local speaker company Kicker. The mobile “sound of science” exhibit will be brought to local schools and industry expos to engage the public with science in an approachable way. Dr. McCullagh’s CAREER award provides an integrated framework for using the auditory system to study important questions related to novel auditory processing mechanisms, as a tool for engaging undergraduates in research, and as a gateway for increasing excitement about science in the public and school system. Dr. McCullagh and her team propose a model in which oxytocin signaling in the sound localization circuit enhances neural sensitivity to allow for quick sound localization to social vocalizations. They will measure the sensitivity of the prairie vole auditory brainstem to different types of acoustic information using prepulse inhibition of the acoustic startle response and complex auditory brainstem response measures with the prediction that animals will be more responsive to prairie vole calls, particularly calls from pair-bonded mates, rather than socially irrelevant tones and that this sensitivity will be reduced or eliminated in oxytocin receptor knockout voles. For oxytocin to influence the auditory brainstem, it must project from other areas and have a cellular consequence. The researchers predict there are neural connections between oxytocin releasing neurons and the auditory brainstem. They will quantify oxytocin and oxytocin receptor expression in areas of the auditory brainstem. The researchers predict oxytocin must be acting through its receptor to change neural responsiveness at a cellular level in this circuit and will test this prediction through measuring auditory brainstem cellular responses in vitro during and after oxytocin application. These experiments will give insight into the mechanisms and connections through which oxytocin is acting on the sound localization circuit to enhance localization ability of specific individuals. 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.