A Cortical Site that Encodes Vocal Expression and Reception.

Area of Science:

• Neuroscience
• Animal Behavior
• Auditory Processing

Background:

• Socially effective vocal communication relies on brain regions processing expressive and receptive vocalizations within specific social contexts.
• The posterior insula (pIns) is implicated in vocal communication, but its precise role in encoding social context-dependent vocal expression and reception remains unclear.

Purpose of the Study:

• To investigate neuronal activity in the posterior insula (pIns) during social vocal communication in mice.
• To determine how pIns activity relates to vocal expression, vocal reception, and social cues.

Main Methods:

• Utilized a novel behavioral assay combined with microendoscopy to monitor neuronal activity in the pIns of socially interacting mice.
• Employed tracing experiments to map neural connections from the pIns to other brain regions involved in vocal control and auditory processing.

Main Results:

• Identified distinct, spatially intermingled neuronal populations in the pIns active during vocal expression and reception.
• Observed that pIns activity precedes vocal onset, suggesting a motor role, and is present even in congenitally deaf mice.
• Found that receptive pIns activity is modulated by social cues, such as female odorants.
• Revealed direct neural connections from deep layer pIns neurons to the auditory thalamus and a midbrain vocal gating region.

Conclusions:

• The posterior insula (pIns) plays a crucial role in encoding both the expressive and receptive aspects of vocal communication.
• pIns neuronal activity is context-dependent, integrating motor signals for vocal production with sensory information modulated by social cues.
• The pIns acts as a critical node, bridging auditory processing and vocalization control within a social context.