Action potential transmitted to presynaptic neurone end
Depolarisation causes Ca2+ voltage gated channels to open + ions diffuse to synaptic bulb
Ca2+ ions stimulate synaptic vesicles (~10,000 acetylcholine) to move to presynaptic membrane
Vesicles fuse w/ membrane + release Ach to synaptic cleft, by exocytosis
Diffuse over synaptic cleft + bind to receptor sites on Na+ channel proteins in postsynaptic membrane
Before binding, postsynaptic membrane polarised
Ach binds to receptor sites, Na+ channels open + Na+ diffuse to postsynaptic neurone
Na+ influx depolarises postsynaptic, generator potential
Ach leaves ion channels, enters acetylcholinesterase enzyme active sites, into ethanoic acid + choline; stimulation is brief
Choline molecules re-enter presynaptic + re-synthesised by ATP
