Dissecting the Cortical Canonical Circuit of Auditory Cortex to Understand Gap Detection

Abstract

Speech comprehension requires processing sound information with a high degree of temporal precision. As a standard metric for assessing temporal acuity, gap detection allows us to understand the neural circuitry involved in such everyday speech processing. Additionally, achieving the finest levels of temporal acuity requires cortical involvement. In the present study, we used a transgenic technique known as optogenetics to manipulate activity in specific subsets of cortical neurons to better understand how cells in different layers of the auditory cortex contribute to brief gap detection. We have also applied neuroanatomical techniques to better understand the position of these populations of cells within the cortical circuit. One such technique utilized fluorescent beads that were retrogradely transported from inferior colliculus and medial geniculate to auditory cortex. This study allows us to verify the cortical canonical circuit in speech processing as well as shed some light on how changes in cortical function contribute to speech pathologies.