What are the events in synaptic transmission?
- The presynaptic action potential reaches the synaptic knob. 2) The terminal is depolarised. 3) Voltage gated calcium channels in the presynaptic knob open. 4) Calcium enters through the calcium channels. 5) This calcium ions cause the fusion of synaptic vesicles to the presynaptic membrane. 6) There is neurotransmitter release e.g. acetylcholine by exocytosis. 7) Acetylcholine diffuses across the synaptic cleft and bind to receptors on the postsynaptic neuron. 8) This causes sodium ion channels in the postsynaptic neurone to open. 9) Sodium ions diffuse in. 10) Excitatory postsynaptic potentials are created. If these generator potentials are sufficient, then the postsynaptic terminal reaches threshold potential and there is propagation.
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