ACETYLCHOLINE synrhesis,storage,release&its regulation,action termination. NOTE :please download it and see it as slide show because it has animations.
6. HOW? Na Choline
Na
Acetyl CoA
Choline acetyl
transferase
Acetylcholine
SYNAPTIC CLEFT
NEURON
Choline
CHOLINE COMES FROM :
* Recycled from Ach degradation
* Phosphatidylcholine breakdown
* Diet
mitochondria
7. WHERE?
IN PRESYNAPTIC VESICLES
WHEN?
AFTER SYNTHESIS
HOW?
The uptake of ACh into storage vesicle occurs through an energy-
dependent pump that acidifies the vesicle. The acidified vesicle
then uses a vesicular ACh transporter (VAChT) to exchange
protons for ACh molecules
H
H H
Ach
Ach
8. WHERE?
FROM THE NEURONAL END TO THE SYNAPTIC CLEFT
WHEN?
WHEN THE ACTION POTENTIAL PASSES THROUGH CELL
MEMBRANE BY ANY STIMULUS
9. Na
K
HOW?
Ca
Action
potential
There is Ca sensitive protein on the vesicle surface(synaptotagmin) and
also in the membrane of the nerve ending (snare complex) Both protein
will interact and contract making the vesicle membrane fuse with the
neuronal membrane and the ACH will release to the synaptic cleft
10. NOTE
THERE ARE SOME TOXINS (e.g. BOTULINUM TOXIN) THAT INHIBIT
THE RELEASE OF THE VESICLES BY INTERACTION WITH SNARE
COMPLEX PROTEINS
11. WHERE?
AT THE SYNAPTIC CLEFT(at Ach receptors in postsynaptic
membrane)
WHEN?
After the activation of the postsynaptic receptors by
binding of Ach, the signal is rapidly terminated.
HOW?
AchE