Many drugs produce their effects by facilitating or interfering with neurotransmitters at synapses.Which of the following drugs would most likely increase the effect of serotonin?
A)A drug that binds to directly coupled serotonin receptors but does not change membrane permeability
B)A drug that prevents the activity of an enzyme that breaks down serotonin molecules in the synaptic cleft
C)A drug that blocks the effect of Ca2+ ions
D)A drug that blocks the effect of a conditional neurotransmitter that normally facilitates the effect of serotonin

Question

Quizplus · Accepted Answer

A drug that prevents the breakdown of serotonin molecules in the synaptic cleft would increase the amount of serotonin available for binding to receptors and increase its effects. Option A would only bind to receptors and not affect the availability of serotonin. Option C would block Ca2+ ions, which are important for neurotransmitter release but not the effect of serotonin. Option D would block the effect of a conditional neurotransmitter, which may or may not affect the effect of serotonin.

Many Drugs Produce Their Effects by Facilitating or Interfering with Neurotransmitters