(324e) Imaging Oxytocin Signaling in Socially Selective Prairie Voles with Non-Genetically Encoded Fluorescent Nanosensors

In social animals, friendships or ‘peer relationships’ with nonreproductive partners play a crucial role in individual health and well-being. However, the neurobiological processes supporting peer relationships remain elusive, in part because of the lack of tools capable of imaging neurochemicals driving such social behavior. Herein, we utilized purely synthetic near-infrared fluorescent nanosensors to image oxytocin, a neuropeptide implicated in social interactions, in live, acute coronal brain slices. The non-genetically encoded nature of these nanosensors enables their use in non-model organisms, allowing applications in prairie voles, a species ideal for social neuroscience because of their selective social relationships with familiar mate partners and with peers. By imaging oxytocin signaling in wild-type and transgenic voles lacking the oxytocin receptor, we observed a reduced number of oxytocin release sites and lower total oxytocin release in the oxytocin receptor null mutant, suggesting that oxytocin signaling is not enhanced but decreased in the absence of functional receptors. Furthermore, behavioral tests revealed that oxytocin receptor knockout mutant females showed no partner selectivity after 24 hours of cohabitation - a duration sufficient to induce partner preferences in wildtype animals. Taken together, this study validated oxytocin imaging in non-model organisms, while providing molecular insights into the role of oxytocin neurochemical communication and oxytocin receptors in peer relationships.