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Harmon, T. C.

Publications and source records attributed to Harmon, T. C..

2 recordsLinked to original sources

Brain-wide mapping of neuroanatomical connections to the auditory cortex of hearing and deaf mice

Remarkable therapeutic innovations have made it possible to establish hearing in congenitally deaf subjects. Despite these advances, a potential obstacle to restoring auditory function is that the absence of auditory experience alters the connectivity of the auditory cortex, a region that contributes to auditory perception and cognition. Here we used an intersectional genetic approach to map the brainwide inputs to the primary auditory cortex of congenitally deaf mice and their hearing littermates. We found that deaf mice displayed a significant reduction in afferents arising from the basomedial amygdala, the core of the medial geniculate nucleus, and anterior auditory thalamic nuclei. Nonetheless, major aspects of auditory cortical connectivity, including input from other thalamic nuclei and from non-auditory regions of the cortex, were unaffected by deafness. These findings highlight altered and preserved connectivity of the auditory cortex in the absence of auditory experience, which may inform therapies designed to establish hearing in congenitally deaf subjects.

neuroscience↗

A Cortical Site that Encodes Vocal Expression and Reception

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 microendoscopy to interrogate neuronal activity in the posterior insula (pIns) in socially interacting mice as they switched rapidly between states of vocal expression and reception. We found that distinct but spatially intermingled subsets of pIns neurons 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 depended strongly on social cues, including female odorants. 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.

neuroscience↗