2. storage in vesicles
3. depolarisation and Ca2+ influx
4. release of transmitter by exocytosis
5. diffusion in synaptic cleft
6. action on post-synaptic receptors
7. effect on post-synaptic cell
8. inactivation/reuptake
There are many, many different transmitters (§4.5). They act on specific receptors ("lock and key").
Sometimes the same transmitter can have different effects, by acting
on different receptor sub-types, e.g. - and - adrenoreceptors (both of
which bind adrenaline and noradrenaline).
Inhibitory post-synaptic potentials (IPSP) - hyperpolarisation.
Post-synaptic potentials may summate (add together) both temporally or spatially.
Temporal summation: summation of PSPs occurring at different times but at the same place.
Spatial summation: summation of PSPs occurring at the same time, but at different places on the cell
Temporal and spatial summation can occur simultaneously, and may involve
both IPSPs and EPSPs. allowing the post-synaptic neuron to act as an information
processor (an 'integrator').
Synthesis of transmitter (1)
Ca influx (3)
Transmitter release (4)
Action of transmitter at receptors on post-synaptic membrane (6)
Breakdown, inactivation, reuptake of transmitter (8)
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