Synaptic transmission Flashcards
What causes the release of neurotransmitter?
Presynaptic action potential
Can neurotransmitters be released even without Nav and Kv channels?
Yes, if membrane can be artificially depolarized
What causes neurotransmitter release during an action potential?
Presynaptic Ca2+ influx via voltage-gated Ca2+ channels
Calmodulin dependent kinase can mobilize neurotansmitters how?
Initiate exocytosis
Replenish releasable pool
What is docking?
Trafficking of transmitters to docking protein, Rab3 (GTP-binding), for release
What is the release mechanism for the storage pool of neurotransmitters
Synapsins link vesicles to cytoskeleton
Calmodulin kinase modulates these links
During Ca2+ influx, Rab3A binds to rabphillin on vesicles and directs them to targetin vsciles & docking site
What proteins are required for transfer of neurotransmitters to releasable pool?
Mammalian uncoordinated-13 (18)
What is the mechanism for release of the slowly releasable/readily releasable pool?
Vesicles dock via v-SNAREs and target t-SNAREs
Name common v-SNARES
synaptobrevin
VAMP
Name common t-SNAREs
syntaxin, neurexin, SNAP-25
What SNARE is targeted by the tetanus toxin?
Synaptobrevin
What SNARE is targeted by the botulinum A toxin?
SNAP-25
What is the function of synaptoagmin?
Modulates Ca2+ dependent exocytosis
Synaptic release of how many vesicles within 1-2ms will depolarize the neuromuscular postsynaptic membrane to 0mV?
100-300
What may account for 90% of neurotransmitter release?
Quantal (spontaneous) release
