Self-vocalizations activate the developing auditory cortex via an intracortical pathway.

Abstract

The development of the sensory brain relies on early periphery-generated spontaneous neural activity and later sensory-evoked activity. To investigate activity sources in the auditory cortex (ACtx) during development, we performed in vivo imaging in neonatal mouse pups. We found self-vocalization-associated ACtx activity even before ear opening and that this activity was stronger than tone-evoked activity. Self-vocalization-associated activity also existed in deaf pups, suggesting a top-down activity source. We revealed projections from the anterior cingulate cortex (ACC) and secondary motor cortex (M2) to the ACtx and that ACC/M2 showed vocalization-driven activity correlated with ACtx activity. ACC/M2 inactivation reduced self-vocalization and ACtx activity. Thus, self-vocalizations activate the developing ACtx even before ear opening, potentially via ACC/M2 motor commands. Our results reveal a previously unidentified early ACtx activity source that can shape development.