乙酰胆碱的生物合成（在胆碱能神经末梢内） COOH HO Mitochondrion NH2 Acetyl-SCo Serine decarboxylate Acetylcholine esynaptic HO NH2 Synaptic vesicle Choline neuron N-methyltransferase N(CH3)3 Synaptic Knob HO CholineCh Synaptic Cleft Choline Ch acetyltransferase otic neur Acetate、 Acetylcholinesterase N(CH3)3 ACh receptor Acetylcholine3 乙酰胆碱的生物合成(在胆碱能神经末梢内) HO COOH NH2 Serine decarboxylate HO NH2 Choline N-methyltransferase HO N(CH3)3 Choline acetyltransferase O N(CH3)3 O Acetylcholine