Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
8 Cards in this Set
- Front
- Back
|
Sequence of Transmission Process at Synapse
|
1. action potential propagated into presynaptic axon terminal
2. voltaged gated calcium (Ca++) channels open and allow calcium entry into terminal 3. calcium causes vesicles to fuse with presynaptic membrane and release transmitter into synaptic cleft 4. transmitter binds to receptor in postsynaptic membrane, directly or indirectly opens ion channels in postsynaptic membrane, resulting in EPSPs or IPSPs -- OR transmitter binds to autoreceptor in presynaptic membrane, decreasing further transmitter release 5. transmitter is either inactivated by enzyme (degraded) or rapidly removed from synapse by reuptake (neuronal or glial) |
|
|
Ligand
|
substance that acts on a receptor
|
|
|
agonist
|
substance that binds to receptor and initiates response like neurotransmitter, acts like ntx, typically used in an artificial sense
|
|
|
antagonist
|
substance that binds to and blocks a receptor and prevents action of ntx
|
|
|
tetrodotoxic (TTX)
|
- toxin that blocks voltage-gated sodium channels
- a kind of antagonist - comes from fish |
|
|
tetrathylammonium (TEA)
|
- blocks voltage-gated potassium channels
|
|
|
fast vs. slow synaptic transmission
|
fast (ligand-gated ion channel) -- direct
1. neurotransmitters bind directly to channels 2. channel opens immediately 3. ions flow across membrane till channel becomes inactivated slow (metabotropic G protein-coupled receptors) -- indirect 1. ntx binds to G protein-coupled receptor 2. G protein is activated 3. activated G protein subunit then moves to adjacent ion channel 4. ions flow across membrane for longer period of time |
|
|
multiple sclerosis (MS)
|
autoiummine disorder in which myelin in CNS is compromised. immune system recognizes own myelin as foreign and starts to destroy it
treatments: - immune modifiers that suppress aspects of the immune system - increase myelin present or induce "some" new myelin to form (oligodendrocytes) |
