Related Experiment Video
Updated: Aug 7, 2026

Transretinal ERG Recordings from Mouse Retina: Rod and Cone Photoresponses
Published on: March 14, 2012
The attenuation of rod signals by bleachings
Abstract:
1. Contrast flash technique allows the rod threshold to be measured even when it lies far above the cone threshold. In this way the rod dark adaptation curve after rhodopsin bleaching can be measured over 6 log units.2. By retinal densitometry the regeneration of rhodopsin can be measured in the same subject. It is found that the log threshold is raised 1.2 units for each 10% of rhodopsin in the bleached state.3. We have tried to discover whether bleaching raises the threshold by desensitizing the rods, or (like backgrounds) by attenuating their signals. Neither suggestion satisfies all conditions.4. All are satisfied by [Formula: see text], where N is the size of rod signal, constant for threshold; theta, theta(D) are steady backgrounds of light and receptor noise; varphi is the threshold flash with sigma a constant of about 2.5 log td sec; B the fraction of pigment in the bleached state.
More Related Videos
Related Concept Videos
The Retina
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
G-Protein Gated Ion Channels
Sensory organs,...
Anatomy of the Eyeball
Photoreceptors and Visual Pathways

