Superior Temporal Resolution of Chronos versus Channelrhodopsin-2 in an Optogenetic Model of the Auditory Brainstem Implant.

Superior Temporal Resolution of Chronos versus Channelrhodopsin-2 in an Optogenetic Model of the Auditory Brainstem Implant. Hear Res. 2015 Jan 15; Authors: Edward Hight A, Kozin ED, Darrow K, Lehmann A, Boyden E, Brown MC, Lee DJ Abstract Contemporary auditory brainstem implant (ABI) performance is limited by reliance on electrical neurostimulation with its accompanying channel cross talk and current spread to non-auditory neurons. A new generation ABI based on optogenetic-technology may ameliorate limitations fundamental to electrical stimulation. The most widely studied opsin is channelrhodopsin-2 (ChR2); however, its relatively slow kinetic properties may prevent the encoding of auditory information at high stimulation rates. In the present study, we compare to ChR2 the temporal resolution of light-evoked responses of a recently developed fast opsin, Chronos in a murine ABI model. Viral mediated gene transfer via a posterolateral craniotomy was used to express Chronos or ChR2 in the mouse nucleus (CN). Following a four to eight week incubation period, blue light (473 nm) was delivered via an optical fiber placed directly on the surface of the infected CN, and neural activity was recorded in the contralateral inferior colliculus (IC). Both ChR2 and Chronos evoked sustained responses to all stimuli, even at high pulse rates. In addition, optical stimulation evoked excitatory responses throughout the tonotopic axis of the IC. Synchr...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research