Figure 1
From: Viral-mediated transduction of auditory neurons with opsins for optical and hybrid activation
Viral-mediated transduction of SGNs with opsins. (A) Expression of EYFP reporter gene in the middle turn of a cochlea from a C57BL/6 mouse injected at a neonatal age. EYFP expression was detected in SGN central fibres (CFs), soma and peripheral fibres (PFs) as far as the synapse with the inner hair cells. (B) The same cochlear section labelled with a ChR2 antibody with notably lower expression in PFs and CFs compared to the SGNs (C) Merged image of EYFP expression (green) and ChR2 antibody labelling (red). (D) Magnified area from central nerve showing punctate ChR2 antibody labelling. (E) Cochlear section from an Anc80-injected mouse that had no detectable EYFP expression. (F) The overall percentage of ChR2-H134R-EYFP transduced SGNs in C57BL/6 mice or guinea pigs (final category) injected via different routes and at different ages. The neonatalC57BL/6 mouse injection group had the highest percentage of transduced SGNs (*p < 0.05 compared to all other groups, Kruskal–Wallis) and the highest proportion of successful transductions overall (Error bars show the standard error of the mean). Scale bar in C applies to images A-C. (SGN = spiral ganglion neuron, EYFP = yellow fluorescent protein; ChR2 = channelrhodopsin-2; RWM = round window membrane; F = fenestration of semi-circular canals; SCC = semi-circular canals; GP = guinea pig). Minor image processing (brightness) was applied equally to the EYFP channel across images for representation purposes.
