Study Set Content:
is the enzyme responsible for the catalysis of our acetylcholine
ChAT
is synthesized in mitochondria, which are present in large numbers in the nerve ending.
ACETYL-COA
• is transported from the extracellular fluid into the neuron terminal by a sodium-dependent membrane choline transporter (CHT).
CHOLINE
This symporter can be blocked by a group of research drugs called
hemicholiniums.
• Once synthesized, acetylcholine is transported from the cytoplasm into the vesicles by a vesicle associated transporter (VAT) that is driven by
proton efflux.
his antiporter can be blocked by the research drug (blank) (is an experimental drug which acts presynaptically inhibiting the acetylcholine uptake into synaptic vesicles to reduce its release).
vesamicol
is a rapid process capable of supporting a very high rate of transmitter release.
Acetylcholine synthesis
Storage of acetylcholine is accomplished by the packaging of "quanta" of acetylcholine molecules (usually (blank) molecules in each vesicle)
1000 to 50,000
Most of the vesicular acetylcholine (ACh) is bound to negatively charged
vesicular proteoglycan
WHAT IS THE MOA OF VESAMICOL? • Inhibits the creation of (blank) from its precursor Acetyl-COA and Choline (by the ChAT choline acetyltransferase enzyme)
Ach
WHICH ION IS REQUIRED FOR THE RELEASE OF THESE NEUROTRANSMITTERS FROM THEIR STORAGE VESICLES???
Calcium ion (Ca2+)
The opening of the pore and inrush of cations results in release of the(blank) from the proteoglycan and exocytotic expulsion into the synaptic cleft.
acetylcholine
One depolarization of a somatic motor nerve may release several hundred(blank) into the synaptic cleft.
quanta
One depolarization of an autonomic postganglionic nerve varicosity or terminal probably releases less and releases it over a
larger area
The acetylcholine vesicle release process is blocked by (blank) through the enzymatic removal of two amino acids from one or more of the fusion proteins
botulinum toxin
After release from the presynaptic terminal, acetylcholine molecules may bind to and activate an
acetylcholine receptor (cholinoceptor).
Eventually (and usually very rapidly), all of the acetylcholine released diffuses within range of an
acetylcholinesterase (AChE) molecule.
• AChE very efficiently splits acetylcholine into
choline and acetate,
AChE very efficiently splits acetylcholine into choline and acetate, neither of which has significant transmitter effect, and thereby (blank) the action of the transmitter
terminates
Most cholinergic synapses are richly supplied with
acetylcholinesterase.
