Frequency-Dependent Inter-Brain Synchrony is Modulated by Social Interaction in Freely Moving Mice

Social interaction, a pivotal aspect of human and animal behavior, involves a dynamic exchange of information that shapes behavioral responses, emotional states, and cognitive processes. To gain insights into the neural mechanisms underlying these processes, it is necessary to simultaneously investigate the brain activity of socially interacting subjects. Commonly, the simultaneous study of behavior and brain activity during the execution of social tasks is conducted through Hyperscanning in humans which limits the availability of interventions. Here we describe a new experimental platform that combines the development of a new miniaturized optical system, the "MiCe-Scope", to monitor neural activity across the entire cortical mantle with a behavioral paradigm to perform a Hyperscanning study in freely moving mice engaged in social interaction. Our results revealed inter-brain synchrony across different frequency bands widespread over the entire cortical mantle, modulated by social behavior. This finding suggests that synchronization reflects the mutual prediction performed by the entire cortex in mice of interacting dyads. The presence of different synchronization maps in these frequency bands suggests a multiscale nature of interaction, extending the predictive nature of interaction to cortical areas beyond the medial prefrontal cortex. Our work provides an experimental framework to conduct Hyperscanning studies in an animal model that mirrors findings from human studies.