FREQUENCY-SPECIFIC OSCILLATORY DYNAMICS AND FUNCTIONAL CONNECTIVITY IN MPFC–NAC CIRCUITS DURING SOCIAL INTERACTION IN MALE MICE

Social interaction is a fundamental component of mammalian behavior that supports social bonding, motivation, and adaptive decision-making. In contrast, impairments in social function are commonly observed in neuropsychiatric disorders such as autism spectrum disorder, schizophrenia, and depression. Moreover, the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) are key components of prefrontal–striatal circuits that regulate social behavior through the integration of cognitive control, motivational, and reward-related processes. Despite this, the neural dynamics and functional coordination within mPFC–NAc circuitry during social interaction remain incompletely characterized. Thus, this study aimed to investigate neural oscillatory activity and functional connectivity between the mPFC and NAc during social interaction in male C57BL/6 mice using local field potential (LFP) recordings. Behavioral analyses revealed that mice preferentially spent more time in the social zone than in the empty zone. Moreover, mean locomotor speed and total distance traveled were significantly reduced during social conditions compared with non-social conditions. In parallel, spectral analyses demonstrated that social interaction was associated with selective increases in fast-frequency oscillatory activity, including significant enhancements in gamma2 (61–100 Hz) power in both the mPFC and NAc. Additionally, theta (5–8 Hz) power in the NAc was significantly increased during social conditions relative to non-social conditions. Finally, coherence analyses revealed increased theta and gamma2 synchrony between the mPFC and NAc during social conditions compared with non-social conditions. Together, these findings suggest that social interaction is associated with frequency-specific modulation of local oscillatory activity and enhanced inter-regional synchronization between the mPFC and NAc.