Synaptic Transmission Flashcards
What are the 9 stages of synaptic transmission?
1- Synthesis and packaging.
2- Na+ action potential invades terminal.
3- This activates voltage gated Ca2+ channels
4- Triggers exocytosis of vesicles
5- Transmitter diffuses across synapse and binds to receptors.
6- Pre-synaptic auto receptors inhibit further transmitter release.
7- Transmitter uptake inactivated by glia and neurones
8- Extracellular breakdown may also occur (ACh)
9- Transmitter metabolised within cells.
What are some methods of reducing synaptic transmission?
Block Na+ voltage gated channels
Block Ca2+ voltage gated channels
Block post-synaptic receptors
Activate presynaptic inhibitory receptors
Inhibit synthesis and packaging of neurotransmitter.
What would happen if you blocked Na+ voltage gated channels?
All axonal conduction would stop on every axon at every synapse. - not very helpful.
Give an example of a drug the blocks Na+ voltage gated channels?
Local anaesthetic.
Give an example of a chemical that blocks Ca2+ voltage gated channels
Spider toxins
Give an example of a chemical that blocks post synaptic receptors?
Receptor antagonists.
What are some methods of increasing synaptic transmission?
Flood cells with the appropriate precursors
Use an allosteric drug that activates the receptor on its own but potentiates the effect of the neurotransmitter.
Block the breakdown of transmitter
Block the uptake of the transmitter.
Give an example of an allosteric drug?
Benzodiazepines/ barbiturates on GABA receptors.
Give an example of a drug that blocks the breakdown of the neurotransmitter?
Anticholinesterases on ACh.
What are the different types of neurotransmitter present within the body?
Acetylcholine Amino acids Monoamines Neuropeptides Nitric oxide Purines
What are some examples of amino acid neurotransmitters?
Glutamate - excitatory
GABA- inhibitory
Glycine
What are some examples of monoamine neurotransmitters?
Noradrenaline
Dopamine
Serotonin
What are some examples of neuropeptide neurotransmitters?
Endorphins
CCK
Substance P
What are some examples of purine neurotransmitters?
ATP
Adenosine
