The concentration of cGMP in a photoreceptor is relatively high in the dark, thereby maintaining rods and cones in the depolarized state.

Question

Quizplus · Accepted Answer

In the dark, the concentration of cyclic guanosine monophosphate (cGMP) is high in photoreceptor cells, which keeps sodium channels open, thus maintaining the cells in a depolarized state. This process is crucial for the dark current and the ability of rods and cones to respond to light.

The Concentration of CGMP in a Photoreceptor Is Relatively High