Administration of a drug that prevents the movement of Ca ++ ions across the neural membrane into the cell is likely to
A)increase neurotransmitter release.
B)decrease the strength of the action potential.
C)decrease neurotransmitter release.
D)increase the strength of the action potential.

Question

Quizplus · Accepted Answer

Ca++ ions play a critical role in triggering the release of neurotransmitters from the presynaptic neuron. When Ca++ channels are blocked, neurotransmitter release is suppressed, leading to decreased neurotransmitter release. This reduces the likelihood of an action potential in the postsynaptic neuron because there are fewer neurotransmitters available to bind to postsynaptic receptors. Therefore, the most likely effect of a drug that prevents the movement of Ca++ ions across the neural membrane will be to decrease neurotransmitter release.

Administration of a Drug That Prevents the Movement of Ca