OXYTOCIN NEURONS DIFFERENTIALLY ENCODE SOCIAL AND NON-SOCIAL REWARDS

The neuropeptide oxytocin (OT) plays a central role in regulating social behavior and bonding; however, the contribution of OT-ergic circuits in choices between social and non-social rewards remains poorly understood. Precise dissection of this circuit is crucial to elucidate the neural mechanisms underlying social behavior and its dysregulation in neuropsychiatric conditions such as autism spectrum disorders and social anxiety. The aim of this study was to determine how hypothalamic oxytocin neurons encode social versus non-social rewards during operant decision-making.
Here, we employed a well-established operant two-choice reward paradigm in female Sprague Dawley rats to examine hypothalamic OT neuron activity during decisions between a palatable sucrose reward and social interaction with a conspecific. Real-time neuronal activity was monitored using in vivo fiber photometry to record calcium dynamics selectively in OT neurons.
Our data show that Sprague Dawley rats consistently prefer sucrose over social interaction under the operant conditions. Fiber photometry results from three different cohorts revealed a robust increase in OT neuronal calcium activity immediately following sucrose consumption, whereas elevated but statistically non-significant OT calcium activity was observed prior to the onset of social interaction. This temporal dissociation may suggest that OT neurons differentially encode reward-related processes depending on the nature of the reward.
Our findings support a broader role for oxytocin signaling in reward-based decision-making across social and non-social domains. Understanding these mechanisms may inform the development of targeted oxytocin-based interventions for disorders characterized by social dysfunction or maladaptive reward processing.