Presynaptic Mechanisms Flashcards
Presynaptic action potential allows increase ___ permeability and influx.
Ca
Presynaptic Ca influx allows release of ___ through exocytosis
Neurotranmsmitter
Ca ion concentration is over ___ times higher in extracellular space than in presynaptic cytoplasm
10,000x
What causes release of neurotransmitter?
Release is a function of ___ influx into the ___ terminal
Ca
Presynaptic
2 functions of Ca on the influx effect:
1- carrier of __ charge
2- special signal carrying information about changes in intracellular structures
Depolarizing
2 functions of Ca on the influx effect:
1- carrier of depolarizing charge
2- special signal carrying information about changes _____
Changes in intracellular structures
Ca influx effect:
Synaptic vesicles have a ____ sensor.
Binding of up to ___ Ca ions required to trigger release
Ca
4
Voltages gated calcium channels are located in ___ zones
Active
S4 segment of calcium channel structure is a (POSITIVE/ NEGATIVE) charged amino acid which acts as a ___ sensor
Positive charged amino acid
Voltage sensor
Calcium channels are found in all ___ cells, in skeletal and cardiac muscle cells, and in endocrine cells
Neuron cells
T-type calcium channels open in response to __ depolarizations
Small
Each Ca synaptic vesicle stores one quantum of neurotransmitter matter…up to ___ molecules
Several thousand
The greater the influx of Ca into the terminal, the larger the number of ___ released
Quanta
GTP-binding protein co-factor is:
Ca
Ca vesicles stored outside of active zone (held in reserve) are anchored by cytoskeleton ___ and activated by____
Synapsins
cAMP
Docking and fusion of vesicles is accomplished by ___ proteins
SNARE
V-SNARE=
Vesicle SNARE protein
T-SNARE=
Target (membrane) protein
T-SNARE complex is comprised of ___+___
Syntaxin
SNAP-25
SNAP+ NSF protein = ____ SNARE complex
Unwind
3 mechanisms of recycling synaptic vesicles:
1- classical uses ___ coated pits and is used for ____rates of release
Clathrine
Normal to high
3 mechanisms of recycling synaptic vesicles:
2: kiss and run, the ___ pore is integrated into the plasma membrane and used at ____ rates
Fusion
Lower to normal release
3 mechanisms of recycling synaptic vesicles:
3) ____ pathway. Retrieves after ___ rate of release.
Bulk endocytosis
High rate
Synaptic plasticity is controlled by 2 processes:
Intrinsic
Extrinsic
