Rods and cones, hyperpolarization?

[slinquii]

I am going over content category 6A in Psych, Soc, and Bio Foundations of behavior, vision...

I am reading that the photoreceptors are the only type of sensory cell that is depolarized when at rest. However, I do not understand why it is considered depolarized. I thought that depolarization simply meant that a cell is becoming less negative (or less polarized) than in its resting state. If it is depolarized in its resting state, then it must not be in its resting state! That is my logic. Please help. Thanks!!

edit: should have made the title: Rods and cones, depolarized at rest?

---

Members don't see this ad.

 

[theonlytycrane]

Detection of light actually turns action potentials off for a lot of photoreceptor cells. This is reverse from other sensory cells. Usually some event (light) depolarizes the membrane to send an AP. In this case light is hyperpolarizing the cell to turn APs off. In either case it's just a method of sending information to the brain about what's going on