Which of the following does not occur in a photoreceptor during exposure to light? A) membrane hyperpolarization B) closure of Na⁺ channels in the outer segment C) increased transmitter release from the synaptic terminal D) decrease in cyclic GMP in the outer segment E) closure of Ca²⁺ channels in the synaptic terminal

Question

Quizplus · Accepted Answer

Exposure to light leads to a decrease in transmitter release from the synaptic terminal of the photoreceptor, not an increase. This occurs because the hyperpolarization of the membrane reduces the influx of Ca2+ ions, which are necessary for transmitter release. A, B, D, and E all occur during exposure to light in a photoreceptor.

Which of the Following Does Not Occur in a Photoreceptor