This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': 'Retinal cells which secrete acetylcholine \nSelect and explain. \nA. Bipolar cells, B. Ganglion cells, C. Amacrine cells, D. H Cells', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The cholinergic amacrine cells of the rabbit retina secrete acetylcholine by two mechanisms. One is activated by stimulation of the retina by light or depolarization of the amacrine cells by K+ ions. It requires the presence of extracellular Ca2+. The second is independent of extracellular Ca2+ and is unaffected by large depolarizations of the cells. It bears some similarity to the acetylcholine &;leakage&; described at the neuromuscular junction. Although the Ca2+-independent mechanism accounts for about two-thirds of the total acetylcholine release in the dark, the amount of acetylcholine released in this way is small compared with the release of acetylcholine triggered by stimulation of the retina with light. Its biological significance is unclear.Ref: Ganong&;s review of medical physiology, 23rd edition, Page no: 182', 'role': 'assistant'}]