Multielectrode array recordings to assess the ChR2-mediated spiking activity of RGCs in response to flickering light stimuli.

<p>A–D) Representative recordings for ChR2-mediated spiking activity for wt-ChR2 (A), L132C (B), L132C/T159C (C), and L132C/T159S (D). In each panel, a raster plot of 10 recordings and an averaged spike rate histogram are shown in the top and bottom panels, respectively. The light intensities used were 0 and 1 ND attenuation for wt-ChR2 and L132C, respectively, and 2 and 2.5 ND attenuation for L32C/T159C and L132C/T159S, respectively. E) The responses from the same L132C/T159S mutant RGC to a higher light intensity with the same frequencies. The ability of the L132C/T159S mutant to follow the flickering light stimuli at all frequencies was deteriorated. The light intensities were measured as photons/cm²s.