Study Set Content:
The half-life of acetylcholine molecules in the synapse is therefore very
short
is also found in other tissues, eg, red blood cells, plasma, liver, ganglia, and many other tissues)
Acetylcholinesterase
WHAT DOES THE INFLUX OF CA2+ INTO THE AUTONOMIC AXON TERMINAL DO?
Increase ACh release from axon terminals.
Adrenergic neurons transport a precursor (blank) into the nerve ending, then synthesize the catecholamine transmitter, and finally store it in membrane-bound vesicles.
amino acid (tyrosine)
In most sympathetic postganglionic neurons, (blank) is the final product.
norepinephrine
In the adrenal medulla and certain areas of the brain, some norepinephrine is further converted to
epinephrine.
In dopaminergic neurons, synthesis terminates with
dopamine
Several processes in these nerve terminals are potential sites o
drug action
is the ratelimiting step in catecholamine transmitter synthesis
The conversion of tyrosine to dopa,
It can be inhibited by the tyrosine analog
metyrosine.
A high-affinity antiporter for catecholamines located in the wall of the storage vesicle (blank) can be inhibited by the reserpine alkaloids
(vesicular monoamine transporter, VMAT)
causes depletion of transmitter stores.
Reserpine
carries norepinephrine and similar molecules back into the cell cytoplasm from the synaptic cleft
Norepinephrine Transporter(NET)
is also commonly called uptake 1 or reuptake 1 and is partially responsible for the termination of synaptic activity
NET
NET can be inhibited by
ocaine and tricyclic antidepressant drugs
NET can be inhibited by cocaine and tricyclic antidepressant drugs, resulting in an (blank) of transmitter activity in the synaptic cleft
increase
As a result, they are avidly taken up into noradrenergic nerve endings by
NET
In the nerve ending, they are then transported by vesicular monoamine transporter VMAT into the vesicles, displacing norepinephrine, which is subsequently expelled into the synaptic space by reverse transport via
NET
also inhibit monoamine oxidase and have other effects that result in increased norepinephrine activity in the synapse.
Amphetamines
Their action does not require vesicle
exocytosis
