Zusammenfassung der Ressource
Chemical Events at the Synapse
- Stage 1- neuron synthesizes chemicals that serve as neurotransmitters.
- Synthesizes the
smaller neurons in the
axon terminals
- Synthesizes the
neuropeptides (chains
of amino acids) in the
cell body
- Stage 2- action potentials travel down the axon. At the presynaptic
terminal, an action potential enables calcium to enter the cell.
- 1-2ms after calcium
enters the
presynaptic terminal,
it causes exocytosis;
the release of
neurotransmitters in
bursts
- Stage 3- the release of molecules diffuse across the cleft, attach to
receptors and alter the activity of the postsynaptic neuron.
- Stage 4- the neurotransmitter molecules may be taken back into
the presynaptic neuron for recycling, or they may be taken away.
- Stage 5- some postsynaptic cells send reverse messages to control
the further release of neurotransmitters by presynaptic cells.
- Sensitive receptors
(autoreceptors) inhibit
further synthesis and
release