Why should bipolar cells prefer graded potentials to action potentials?
My attempt: I know that graded potentials are better in processing information since stimulus is directly proportional to response generated unlike action potential where the response is always same.
Reasons: But I don't understand its need in bipolar cells , because graded potentials have already been generated in rods and cones. Also the final message coming out of eye is in the form of action potentials from ganglion cells. If graded potentials were of that importance then why they do stop at bipolar cells and continue as action potentials in the later pathway?
Finally, graded potentials are slower than action potentials so latter should be preferred in places like eyes where response is needed to be quick.