The mouse posterior insular cortex encodes expressive and receptive aspects of courtship vocalizations

Socially effective vocal communication requires brain regions that encode expressive and receptive aspects of vocal communication in a social context-dependent manner. Here, we combined a novel behavioral assay with microendoscopic calcium imaging to interrogate neuronal activity (regions of interest [ROIs]) in the posterior insula (pIns) in socially interacting mice as they switched rapidly between states of vocal expression and reception. We found that largely distinct subsets of pIns ROIs were active during vocal expression and reception. Notably, pIns activity during vocal expression increased prior to vocal onset and was also detected in congenitally deaf mice, pointing to a motor signal. Furthermore, receptive pIns activity was modulated strongly by social context. Lastly, tracing experiments reveal that deep-layer neurons in the pIns directly bridge the auditory thalamus to a midbrain vocal gating region. Therefore, the pIns is a site that encodes vocal expression and reception in a manner that depends on social context.