This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'All of the following statements regarding activity at the neuromuscular junction are true except: \nSelect and explain. \nA. Action potentials on the alpha motor neuron release acetylcholine (Ach) from the axon terminal, B. Ach stimulates nicotinic cholinergic receptors on the muscle endplate, C. Cholinergic receptors on the muscle endplate are cation channels, D. Alpha motor neurons excite, and Renshaw cells inhibit, the muscle endplate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There are no Renshaw cells at the neuromuscular junction. Renshaw cells inhibit motor neurons in the anterior gray horn of the spinal cord. Action potentials on the alpha motor neuron release acetylcholine (ACh) from the axon terminal. The ACh diffuses across the synaptic cleft and stimulates nicotinic receptors on the muscle endplate, generating an action potential that causes contraction of the muscle fiber. Cholinergic receptors on the muscle endplate are cation channels.', 'role': 'assistant'}]