Synapses and neurotransmitters 3 Flashcards
What is ChAt?
Choline acetyltransferase
What process is acetyl CoA produced in? In what structure?
Cellular respiration in mitochondria
What is the equation for the production of acetyl choline?
Acetyl CoA + Choline -> ACh
Via ChAt
What is an nAChRs?
An ACh gated Na+/Ca2+ channel
Where are nAChRs found?
At neuromuscular junctions in CNS
What are mAChRs?
G protein coupled receptors
How many types of mAChRs are there?
5 types :
M1 , M2, M3, M4, M5
What is M1,2&3 mAChRs mechanism of action?
Exitatory via Gq
What is M2&4 mAChRs mechanism of action?
Inhibitory via Gi/o
What AChRs are ionotropic?
nAChRs
What AChRs are metabotropic?
mAChRs
What happens when an ionotropic channel opens?
They allow a positive current into the cell which leads to depolarisation
What is the function of a junctional fold?
Concentrate receptors to the correct place
What drug blocks the release of acetylcholine?
Botulinum toxin
Describe the mechanism of the botulinum toxin
Prevent acetylcholine from reaching motor nerves and causes paralysis
What drugs blocks the release of AChE (acetylcholinesterase)?
Nerve gas
Organophosphate pseticides
What is the equation for the production of acetic acid?
ACh -> Acetic acid + Choline
Via acetylcholinesterase
Describe the mechanism of nerve gas
Acetylcholinesterase inhibition causes Acetyl choline to build up ->
Leads to paralysis of the muscles and seizures in insects
What drug activates ACh receptors?
Neonicotinoid pesticides
Muscarine
Nicotine
What drugs block nAChRs?
Curare
Alpha bungarotoxin
What drug block mAChRs?
Atropine
Why is atropine used to treat nerve gas poisoning?
Atropine occupies mAChRs which reduces the effects of excess acetylcholine build up
What are monoamine synthesised from?
Amino acids
What molecule is serotonin synthesised from?
Tryptophan
What packages monoamines into vesicles?
Vesicular monoamine transporters
How are monoamine removed from the synaptic cleft?
They are taken up by monoamine specific re-uptake transporters
How are monoamines destroyed?
Metabolised by MAO
Metabolised by COMT on postsynaptic cells for catecholamines