When a neurotransmitter molecule binds briefly with a receptor site, changes occur in the receiving neuron's charge. If there is a voltage shift in a negative direction, then the effect is:
A) inhibitory, and so the probability that the receiving neuron will fire decreases.
B) excitatory, and so the probability that the receiving neuron will fire increases.
C) inhibitory, and so the probability that the receiving neuron will fire increases.
D) excitatory, and so the probability that the receiving neuron will fire decreases.

Question

Quizplus · Accepted Answer

When there is a voltage shift in a negative direction, it means that the neuron is becoming more negative, which makes it harder to reach the threshold required for firing an action potential. Therefore, the effect is inhibitory, and the probability that the neuron will fire decreases.

When a Neurotransmitter Molecule Binds Briefly with a Receptor Site