4. Neurotransmitters Flashcards
what was the first neurotransmitter to be discovered
acetylcholine
how is acetylcholine synthesised
Aectyl coA + choline → acetylcholine
by action of choline acetyl transferase
name the two types of acetylcholine receptors
nicotinic
muscarinic
where do u find nicotinic receptors
neuromuscular junctions, brain, autonomic nerves
where do u find muscarinic receptors
smooth muscle, exocrine glands, brain
how is acetylcholine function affected in Alzheimers disease
cholinergic neurons die early
- important in memory and attention
what is a treatment for AD
acetylcholinesterase inhibitors- more time for Ach to bind to receptors
give two examples of catecholamines
dopamine and norepinephrine
what a catecholamines synthesised from
tyrosine
what are the two families of dopamine receptors
D1-like = D1 & D5 D2-like= D2,D3,D4
what are D1-like receptors coupled to
stimulatory G-proteins
what are D2-like receptors coupled to
inhibitory G-proteins
what happens to dopamine in Parkinson’s diease
degeneration of dopaminergic neurons= 50% depletion of dopamine
how are motor symptoms of dopamine treated
L-dopa
-transported to the brain and converted to dopamine
dopa decarboxylase inhibitor
- prevents premature conversion of l-dopa to dopamine
what is serotonin synthesised from
tryptophan
what are the majority of serotonin receptors
14 g-protein coupled receptors
5-HT^3 → ligand gated ion channel
name two amino acid neurotransmitters
Glutamate and GABA
GABA receptors are inotropic, explain how this makes GABA inhibitory
GABA receptors are coupled to chloride channels, when GABA binds, chloride channels open and cl- enters the cell lowering the charge away from threshold potential
what enzyme converts glutamate into GABA
glutamate decarboxylase
what are the three different types of glutamate receptors- give a very brief description
NMDA receptor- binds many molecules
non-NMDA receptor- interacts only with glutamate
mGlut receptor- GPCR
what removes astrocytes from the synapse
astrocytes
where are peptide neurotransmitters most commonly used
hypothalamus
what other molecules can act as neurotransmitters:
purines, histamine, nitric oxide
