What does the presynaptic terminal contain
vesicles
mitochondria
Quantal vesicle release
What do postsynaptic membranes contain
neurotransmitter receptors (ligand-gated)
Voltage-gated channels
What does the mitochondria at the synaptic terminal do
supply energy demand
Ca2+ buffering
What is the main uses of Ionotropic receptor proteins
fast signal transmission
What is the main uses of metabotropic receptor proteins
amplification
neuronal modulation
slow by 2nd messenger
what are the two types of neurotransmitter’s synthesis site, vesicles, release, inactivation
Small molecule: axonal terminal or varicosity, small clear vesicles, low-freq stimulation, reuptake or specific enzymes
Peptide: nucleus/ER propeptide, Large dense-cored vesicles, high-freq. stimulation, extracellular peptidases.
What are the targets of 30-40% of drugs
GPCR’s
What is a catecholamines
class of neurotransmitters and hormones
-benzene ring with 2 adjacent OH groups
What is the parent molecule for catecholamines; and what are the resultant catecholamine neurotransmitters
Tyrosine; dopamine, norepinephrine, epinephrine
How does tyrosine get converted into dopamine
tyrosine catalyzed by tyrosine hydroxylase (adds OH; RATE LIMITING ENZYME)–> Dihydroxyphenalanine (DOPA, a catecholamine) catalyzed by DOPA dexarboxylase –> Dopamine
Describe dopamine receptors
5 classes
GPCR’s
all metabotropic
Describe the dopamine transporter
cotransporter
Dopamine x Na+ in
What does a Quantal vesicle release mean
a full release of contents in a vesicle into a synapse
What does the synaptic cleft contain
Acetylcholinesterase
What is an EPSP
Excitatory Post Synaptic Potential
mini EPSPs are random, single units
evoked EPSPs result from many vesicles releasing
What is the amplitude of mEPSP
0.4-1.0 mV released quantal
How is the muscle fiber depolarized
low Ca2+, high Mg2+
each AP releases only a few quanta of neurotransmitter
Na/K through the same channel
What is a SNARE complex
molecular motors that drive the biological fusion of pre and postsynaptic membranes.
contains several proteins to facilitate vesicle docking on active zone
What are the proteins part of the SNARE complex
Synaptobrevin: vesicle membrane
Syntaxin: localized on plasma membrane
SNAP-25: localized on plasma membrane
What are the sequence of events of vesicle trafficking at the synaptic terminal
Action potential arrives at the axonal terminal, depolarizing it.
▪ Voltage gated Ca2+ Channels open and Ca2+ enters the terminal.
▪ Synaptotagmin, a calcium sensor, binds Ca2+
.
▪ Ca2+
– Synaptotagmin complex binds to the SNARE complex and induces
pore formation
Describe exocytosis and neurotransmitter release
vesicle fusion increases membrane capacitance
neurotransmitter binds to receptors on post synaptic membrane
What does clathrin do for vesicle trafficking
coats vesicle membrane to facilitate endocytosis of vesicle, to golgi, reassembled to trans-golgi network
HIGH rates of neurotransmitter release
What is the kiss and run pathway
after synaptic vesicle has descharged, it is quickly retrieved: LOW rates of neurotransmitter release
What are the 5 steps of synaptic vesicles
- mobilization
- docking
- priming
- exocytotic fusion
- endocytosis
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Chapter 149
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1.259
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1.343
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Lecture 1056
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Lecture 1123
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Lecture 1233
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Lecture 1330
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Lecture 1440
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Lecture 1545
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Lecture 1622
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Lecture 1721
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Lecture 1826
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Lecture 1932
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Lecture 2053
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Lecture 2136
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Lecture 2248
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lecture 2321
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lecture 2476
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lecture 2543
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lecture 2654
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Lecture 2741
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Lecture 2851
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lecture 2948
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Lecture 3046
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Lecture 3138
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Lecture 3230
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Psychedelics25
