Functional specialization of mPFC-BLA and mPFC-NAc pathways in affective state representation

Effective emotional processing, crucial for adaptive behavior, is mediated by the medial prefrontal cortex (mPFC) via connections to the basolateral amygdala (BLA), and nucleus accumbens (NAc), traditionally considered functionally similar in modulating reward and aversion responses. However, the functional specialization of the mPFC→BLA and mPFC→NAc pathways in representing affective states remains unclear. We found that while overall firing patterns appeared consistent across emotional states, deeper analysis revealed distinct variabilities. Specifically, mPFC→BLA neurons, especially 'center-ON' neurons, exhibited heightened activity during behaviors classically associated with anxiety-like states, suggesting their involvement in aversive behavioral regulation. Conversely, mPFC→NAc neurons were more active during exploratory and approach-related behaviors, implicating them in the processing of positively valenced behavioral states. Notably, mPFC→NAc neurons showed significant pattern decorrelation during social interactions, suggesting a pivotal role in processing social preference. Additionally, repeated win/loss outcomes in the tube test produced distinct hierarchy-dependent behavioral changes and elevated corticosterone levels in loser mice, supporting the biological relevance of these behaviorally defined states. Together, these findings reveal pathway-specific representations of affect-related behavioral states in mPFC circuits and provide a framework for understanding how prefrontal outputs organize adaptive behavior across environmental contexts.