Which event would make it less likely for a postsynaptic muscle cell to fire an action potential? A) Failure of Ca²⁺ to trigger exocytosis in the axon terminal of the presynaptic motor neuron B) Inhibition of acetylcholinesterase in the synaptic cleft C) Opening of voltage-gated Na⁺ channels and entrance of Na⁺ into the cell D) Binding of acetylcholine to its receptors in the motor end plate E) An increase in excitatory inputs

Question

Quizplus · Accepted Answer

If Ca2+ fails to trigger exocytosis of neurotransmitters from the presynaptic motor neuron, there will be a lack of neurotransmitters (such as acetylcholine) released into the synaptic cleft. This means there will be no ligand-gated ion channels opened in the postsynaptic membrane, which will make it less likely for the muscle cell to fire an action potential.

Which Event Would Make It Less Likely for a Postsynaptic