Synaptic Transmission Flashcards
Glutamate Synthesis in astrocyte:
Glutamate (glutamine synthetase) Glutamine (glutaminase) Glutamate
dopamine B-hydroxylase (DBH)
Creates: norepinephrine
Dopamine –> norepinephrine
amino acid decarboxylase
Creates: seratonin
5-hydroxytryptophan –> 5-hydroxytryptamine (seratonin)
choline acetyltransferase
Combines:
Acetylcoenzyme A + choline =
ACh
glutamine synthetase
Creates: glutamine
glutamate –> glutamine
glutaminase
Creates: glutamate
glutamine –> glutamate
Seratonin Synthesis
Tryptophan (tryptophan hydroxylase) 5-hydroxytryptophan (amino acid decarboxylase) 5-hydroxytryptamine (seratonin)
Dopamine, Norepinephrine, Epinephrine Synthesis
Tyrosine (tyrosine hydroxylase) dihyroxyphenylalanine (DOPA) (DOPA-decarboxylase) Dopamine (dopamine B-hydroxylase, DBH) Norepinephrine (phenylethanolamine-N-methyl-transferase, PNMT) Epinephrine
l-glutanic acid-1 decarboxylase
Creates: GABA
Glutamate –> GABA
DOPA-decarboxylase
Creates: dopamine
DOPA –> dopamine
Mechanisms terminating NT (5)
- Enzymatic degredation
- Reuptake transporters
- Autoreceptors
- Diffusion
- Glial cells
Gamma aminobutyric acid (GABA) Synthesis
glutamate
(l-glutanic acid-1 decarboxylase)
Gamma aminobutyric acid
tyrosine hydroxylase
Creates: dihyroxyphenylalanine (DOPA)
Tyrosine –> DOPA
acetylcholinesterase
(inhibited by sarin)
Creates: Acetylcoenzyme A + choline
Starts as: ACh
Criteria for NT (4)
- Synthesized in neuron
- Must be present in presynaptic t. and release must exert an action on postsynaptic
- Exogenous application must mimic effects
- Specific mechanism for removal
GABA transaminase (GABA-T)
From: GABA to glutamate
ACh Synthesis:
Glucose (glycolysis) Pyruvate Acetyl group + coenzyme A Acetylcoenzyme A Acetylcoenzyme A + choline (choline acetyltransferase) Acetlycholine
phenylethanolamine-N-methyl-transferase (PNMT)
Creates: Epinephrine
Norepinephrine –> Epinephrine
VAMP (synaptobrevin)
syntaxin
SNAP-25
synaptotagin (p65)
v-SNARE, cleaved by Botulinum toxin B and tetanus toxin
t-SNARE, cleaved by Botulinum toxin C
t-SNARE, cleaved by Botulinum toxin A
May be V-SNARE, Ca sensor
tryptophan hydroxylase
Creates: 5-hydroxytryptophan
tryptophan –> 5-hydroxytryptophan