The sodium leak channels in photoreceptors are cyclic GMP-gated channels. What must occur during activation of photoreceptor cells by light?

Question

Quizplus · Accepted Answer

When photoreceptor cells are activated by light, an enzyme called phosphodiesterase (PDE) is activated, which breaks down cyclic GMP into inactive GMP. This reduction in cyclic GMP levels causes the sodium leak channels to close, leading to hyperpolarization of the cell and ultimately triggering the visual signal transduction pathway in the retina.

The Sodium Leak Channels in Photoreceptors Are Cyclic GMP-Gated Channels