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Updated: Jun 8, 2026

Simultaneous ex vivo Functional Testing of Two Retinas by in vivo Electroretinogram System
Published on: May 6, 2015
Endogenous nitric oxide enhances the light-response of cones during light-adaptation in the rat retina
Masaki Sato1, Teruya Ohtsuka, William K Stell
1Biology Research Division, Graduate School of Science, Toho University, 2-2-1 Miyama, Funabashi, 274-8510 Chiba, Japan.
Abstract:
The electroretinogram (ERG) is a non-invasive indicator of retinal function. Light flashes evoke a cornea-negative a-wave followed by a cornea-positive b-wave. Light-adaptation is known to increase the amplitude of cone-dependent b-waves. To identify the underlying mechanism, we recorded rat cone photoresponses in situ, using intravitreally-injected glutamate to block synaptic transmission and intense paired-flash stimuli to isolate cone a-waves. Steady adapting illumination caused a progressive increase in cone a-wave amplitude, which was suppressed in a dose-dependent manner by intravitreal CPTIO, a nitric oxide scavenger. We conclude that light-adaptation causes release of nitric oxide, which enhances the cone photoresponse.
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