Applied Neuro-Pharmacology Flashcards
Synthesis and packaging of neurotransmitter usually occurs in
presynaptic terminals
Na+ action potential invades the terminal and activates
voltage gated Ca2+ channels
Activation of Ca2+ channels triggers
calcium dependent exocytosis of pre-packaged vesicles of neurotransmitter
Neurotransmitter diffuses across the cleft and binds to
ionotropic and/or metabotropic receptors to evoke postsynaptic response
Presynaptic autoreceptors inhibit
further transmitter release
Acetylcholine receptors
Nicotinic
Muscarinic
Serotonin receptors
5-HT
Dopamine receptors
D1, D2, D3, D4, D5
Noradrenaline receptors
Adrenergic
GABA receptors
GABAA, GABAB
Glycine receptors
NMDA
Tyramine receptors
TA1
Glutamate receptors
NMDA
What effect will pharmacologically blocking voltage gated Na+ channels have?
e.g. local anaesthetics
Will block action potentials of all neurones in that region so reduce synaptic transmission
What effect will pharmacologically blocking voltage gated Ca2+ channels have?
e.g. spider toxins
Will block all transmitter release, stopping Ca from entering presynaptic terminals and stopping transmitter release
Block all synaptic transmission
How could you increase synaptic transmission pharmacologically?
Increase synthesis Use an agonist to activate postsynaptic receptors Use allosteric drug to activate receptor Block breakdown of transmitter Block uptake of transmitter
What effect will using an allosteric drug that activates the receptor have?
Potentiate effects of endogenous transmitter on receptor
Increase channel open time
Increase synaptic transmission
Why does a single neurotransmitter have multiple functions in different regions?
Limited range of neurotransmitters
Dopamine is anatomically distributed in what 3 main areas of the brain?
Brain stem
Basal ganglia
Limbic system and frontal cortex
What are the physiological functions affected by dopamine in its anatomical distributions?
Brain stem - vomiting
Basal ganglia - voluntary movement
Limbic system and frontal cortex - emotions
Why won’t dopamine work if given orally/IV?
Neurotransmitters cannot cross the blood-brain barrier
Why can’t dopamine evoke fast EPSPs or IPSPs?
It has no ionotropic receptors
Dopaminergic drugs
Levodopa Bromocriptine/pergolide Ropinirole Pramipexole Apomorphine
Enzyme inhibitors which can be given with dopaminergic drugs
Peripheral AAAD inhibitors e.g. carbidopa
MAO-B inhibitors e.g. selegiline
COMT inhibitors e.g. entacapone
Effects of dopaminergic drugs
Can improve Parkinson’s disease symptoms but can worsen/cause nausea, vomiting and psychosis
