Ligand gated ion channels II Flashcards
Glycine receptor is a heteropentamer, how many alpha subunits does it have?
3
What are agonists of the glycine receptor? Antagonists?
Glycine, Taurine
Strychnine
Where does ligand binding occur on the glycine receptor?
N terminus of alpha subunit
What ion is glycine permeable to?
Chloride
What modification regulates activity of glycine receptor?
Phosphorylation (PKA,PKC, Tyrosine kinase)
How many alpha subunits does GABA have?
2
What is the intracellular enzyme involved in targeting for Gly and GABA receptors?
Gephyrin
What is the cause of stiff baby syndrome?
Mutation in Gly targeting
What happens when Gly/GABA receptors are activated?
membrane potential is slightly depolarized (-77mV)
What happens when Gly/GABA receptors are activated along with Ach receptors?
Depolarization is less than is would be with Ach alone
How is Gly inhibitory?
Stabilizes membrane potential and reduces depolarization during cation permeability
What is the purpose for multiple binding sites?
No incidental activation
If a receptor has 3 binding sites, and 33% are occupied, what % is open?
4%
What is the presynaptic uptake receptor for Glycine?
GlyT2
What is the perisynaptic uptake receptor for Glycine?
GlyT1
What is the presynaptic uptake enzyme for GABA? Perisynaptic?
GAT1
GAT3
What is the enzyme that breaks down acetylcholine?
Cholinesterase
What is the enzyme that breaks down serotonin?
Monoamine oxidase
What is the uptake receptor for serotonin?
SERTs
What modifications to receptors result in a termination of response?
Dissociation
Desensitization
Down regulation
What are the ways transmitters can be removed?
Breakdown/metabolism
Diffusion from cleft
Reuptake
Why does glycine hyperpolarize if the math says depolarization should occur?
Stabilizes nerve cell to prevent signal propagation (action potential reduction)
What is the result of an inverse agonist?
Basal activity is reduced
In the parasympathetic pathway the first neurotransmitter is what, and the second transmitter is what?
Acetylcholine
Acetycholine
In the sympathetic pathway, the first neurotransmitter is what and the 2nd transmitter is what?
Acetylcholine
Epinephrine
