Primary and secondary auditory cortex connectivity with brain regions involved in cognitive and emotional processing: in mouse and human

Auditory cortex connections go beyond the processing of acoustic stimuli and play a critical role in cognitive and emotional regulation through their interactions with higher-order brain regions. Although the neural mechanisms of acoustic information processing along the auditory pathway are well documented, the connections that support hearing-related cognitive and emotional processing — particularly in studies comparing mouse and human adults — have not yet been fully clarified.

In this study, the connections between the auditory cortex and brain regions involved in cognitive and emotional processing were investigated using a retrograde fluoro-gold (FG) tracer in mice and 3-tesla high-resolution diffusion tensor tractography (DTI) in human adults. FG injections into the primary (AI) / secondary (AII) auditory cortex showed afferent connections with cortical, subcortical (amygdala, hippocampus, globus pallidus, etc.) and brainstem structures. DTI data obtained from human adults largely overlapped with the experimental findings.

The auditory cortex may be a critical hub within the neural circuit underlying multisensory integration, decision-making, prediction, learning and memory functions. Understanding the connections of the auditory cortex may offer new perspectives on the mechanism linking hearing loss to cognitive/emotional disorders.