This research is focused on assessing the inferior colliculus central nucleus (ICC) to primary auditory cortex (A1) neural projection using electrical stimulation (ES) of the ICC in a guinea pig model, in light of the development of a midbrain auditory prosthesis (MAP). Due to limitations of current auditory prostheses and the potential for improvements in frequency and level discrimination by ES of the ICC, experiments to determine the feasibility for a MAP are of interest. Therefore, it is important to study how the central auditory system organizes and processes sound information to assess how we might implement a MAP to achieve intelligible speech perception. A point-to-point tonotopic projection from the ICC to A1 has been shown. Thus, multi-channel electrodes will be used to electrically stimulate different ICC regions and simultaneously record neural activity across A1 to determine: (1) if segregated, parallel pathways from the ICC to A1 exist along the isofrequency dimension; and (2) if the temporal activation pattern along an isofrequency contour of A1 changes in response to ES of different regions within an isofrequency lamina of the ICC. ? ?
