Neurotransmitters and pharmacology Flashcards
Classes of neurotransmitters?
Amino acids, amines and neuropeptides.
When neurotransmitter binds to the post synaptic receptor, what does this result in?
Action potential in the post synaptic neurone. Sodium influx in post synaptic neurone.
Explain neurotransmitter release
Docking of vesicle containing neurotransmitter in synaptic zone. Ca2+ entry leading to membrane fusion and exocytosis
How does alpha latrotoxin act as a neurotoxin?
Activates calcium channels. Massive neurotransmitter release resulting in muscle cramping.
How does botulinum toxin act as a neurotoxin?
Inhibits vesicle exocytosis. Paralysis, no muscle contraction.
Two types of post synaptic receptors?
Ion channel linked receptor and g protein-coupled receptor.
Nature of response in post synaptic ion channel linked receptors?
Fast response.
Nature of response in post synaptic g protein-coupled receptors?
Slow response.
What is the main neurotransmitter and post synaptic neurotransmitter receptor in the CNS?
Glutamate and GABA receptor.
What is the main neurotransmitter and post synaptic neurotransmitter receptor in the NMJ?
Acetylcholine and nicotinic receptors.
Examples of g protein coupled receptors?
Seretonin receptors, Dopamine receptors, noradrenaline receptors,
Muscarinic receptors (acetylcholine).
Main Inhibitory neurotransmitters in CNS?
GABA and glycine.
Main excitatory neurotransmitter in CNS?
Glutamate.
Are nicotinic receptors excitatory?
Nicotinic receptors are always excitatory.
How can a receptor excite a neurone?
Lead to sodium influx.
How can a receptor inhibit a neurone?
Lead to hyperpolarisation. With GABA and glycine its a chloride influx.
What are the two types of glutamate receptors?
AMPA and NMDA.
NMDA vs AMPA in terms of influx of ions?
NMDA receptors activation results in the influx of calcium ions in addition to the sodium. AMPA is just sodium.
NMDA vs AMPA in terms of function?
NMDA is responsible for slow component of excitatory transmission while AMPA is responsible for majority of fast excitatory synapses.
What do glutamate receptors require to work?
Glycine bound to receptor.
What cell is involved in the reuptake of neurotransmitter?
Glial cell.
What are seizures associated with?
Excess glutamate.
Why is glutamine synthetase important?
Glutamate to glutamine conversion in glial cells. Reduces excess levels of glutamate in synapse and so no seizures.
Explain a synaptic transmission involving glutamate?
Glutamate reversibly binds postsynaptic receptors. Rapid uptake of glutamate by excitatory amino acid transporters on presynaptic terminal and glial cell. Glutamate enzymatically modified by glutamine synthetase to glutamine in glial cells
How is GABA synthesised?
GABA synthesised by decarboxylation of glutamate by glutamic acid decarboxylase (GAD).
Explain a synaptic transmission involving GABA?
GABA reversibly binds post-synaptic receptors. Rapid uptake of GABA by GABA transporters on presynaptic terminal and glial cell. GABA enzymatically modified by GABA-transaminase to succinic semialdehyde in glial cells.
