How are action potentials transmitted across synapses using neurotransmitters such as acetylecholine?

Action potential causes depolarisation of the pre-synaptic membrane. Opens voltage gated Ca²⁺ and Ca²⁺ floods in to the pre-synaptic knob. Ca²⁺ binds vesicles containing acetylcholine to microtubules. These vesicles then migrate to the cell membrane and fuse with it, causing exocytosis of acetylcholine. Acetylcholine then diffuses across the synapse and binds with ligand gated Na⁺ receptors/ channels.These channels open allowing an influx Na⁺ which causes rapid depolarisation of the post-synptic membrane and generation of an action potential.The acetylcholine bound to receptors and remaining in the synapse is broken down by acetylcholinesterase to prevent overstimulation of the post-synaptic neurone. This is then reabsorbed by the pre-synaptic neurone and remade into acetylcholine.