Introduction:
The auditory brainstem implant (ABI) bypasses the auditory periphery to electrically
stimulate the cochlear nucleus and provides sound perception in pediatric and adult
patients who do not qualify cochlear implant (CI) surgery. However, ABI outcomes continue
to lag behind CI outcomes for reasons that are not fully understood. Most ABI users
achieve sound awareness that enhances lip-reading but only a few patients achieve
open set speech perception. We hypothesize that limited ABI performance can be linked
to broad electrical current spread and unfocused activation along the tonotopic axis
of the cochlear nucleus. This fundamental limitation might be circumvented if light
is used to activate brainstem neurons rather than electrical current and conformable
rather than rigid surface electrode arrays are used to improve the electrode/tissue
interface.
Methods:
Data from acute and chronic studies of our novel ABI animal model, using a conformable
ABI electrode.
Results:
We will demonstrate 1) optogenetic control of central auditory pathways is feasible,
2) fast opsins can be driven with pulsed light in vivo with spatio-temporal precision,
3) optogenetic auditory implants are perceptually salient, and 4) conformable electrical
surface arrays improve performance over rigid designs.
Conclusions:
We developed a novel optogenetic auditory implant for activation of auditory brainstem
neurons and restoration of auditory circuits.
