Under Which Condition Would the Release of Neurotransmitter by Photoreceptors

Question

Under which condition would the release of neurotransmitter by photoreceptors be greatest?
A) under normal room light
B) in a pitch-black room after 30 minutes
C) immediately after going outside in bright sunlight
D) focusing intently on a close object
E) focusing intently on a distant object

Accepted Answer

Photoreceptors (rods and cones in the retina) release the most neurotransmitter in the dark. This is because, in the absence of light, photoreceptors are depolarized, leading to the release of neurotransmitters. When light is present, it hyperpolarizes the photoreceptors, reducing neurotransmitter release.