Lecture 11 (2/15) Flashcards
NMDA receptor is a ______ detector.
NMDA receptor is a coincidence detector.
Collinrige LTP discovery
NMDA receptor antagonist APV inhibits LTP
Lynch LTP discovery
Chelating postsynaptic Ca2+ inhibits LTP
2 common LTP protocols
1) ________ stimulation
2) _________ stimulation paired with _________
2 common LTP protocols
1) tetanus (high frequency) stimulation
2) low frequency stimulation paired with post synaptic membrane depolarization
Opening of NMDArs requires
1) Presynaptic ______ release
2) Postsynaptic __________
1) Presynaptic glutamate release
2) Postsynaptic depolarization
For CaMKII, when the stimulus is weak, there is activation _________.
When the stimulus is strong, there is activation ___________.
For CaMKII, when the stimulus is weak, there is activation without autophosphorylation.
When the stimulus is strong, there is activation by autophosphorylation.
What is the significance of T286?
T286 phosphorylation impairs the inhibitory effect of the regulatory subunit, so that the activity of the phosphorylated subunits persists even after Ca2+/calmodulin dissociates.
The processing creates a “memory” in the CaMKII molecule, until phosphatases erase this persistent kinase activity by dephosphorylation T286.
Mechanisms through which CaMKII activation leads to LTP
1) Phosphorylation of AMPArs increases their _________
2) Promote trafficking of _________ into synapse
3) Phosphorylate __________ at the postsynaptic density (PSD) to create docking sites for AMPArs in postsynaptic membrane
4) Activating _________ and expressing ________ for long-lasting functional and structural changes in synaptic efficacy
Mechanisms through which CaMKII activation leads to LTP
1) Phosphorylation of AMPArs increases their ionic conductance
2) Promote trafficking of intracellular AMPArs into synapse
3) Phosphorylate scaffold proteins at the postsynaptic density (PSD) to create docking sites for AMPArs in postsynaptic membrane
4) Activating transcription factors and expressing new genes for long-lasting functional and structural changes in synaptic efficacy
The promotion of actin polymerization in the head and neck of dendritic spines causes:
1) Creates available slots for ___________
2) Create _________ for supporting the transport and ultimate fusion of AMPA receptor-containing vesicles in the spine head
The promotion of actin polymerization in the head and neck of dendritic spines causes:
1) Creates available slots for synaptic AMAPrs
2) Create additional tracks for supporting the transport and ultimate fusion of AMPA receptor-containing vesicles in the spine head
NMDA receptor is a _______ detector
coincidence
Induction of LTP in CA1 neurons shows cooperativity, which is
The nearly simultaneous activation of a large number of afferent axons to induce LTP
Induction of LTP in CA1 neurons shows associativity, which is
A synaptic modification in one afferent input to a neuron that is conditional upon coactivity in a separate input to the same neuron.
Induction of LTP in CA1 neurons shows synapse specificity, which is
3 characteristics present in induction of LTP in CA1 neurons
1) Cooperativity
2) Associativity
3) Synapse specificity
The low-frequency tetanus stiumulus induces ________ at Schaffer collateral synapses.
The low-frequency tetanus stiumulus induces long-term depression at Schaffer collateral synapses.
5 steps for LTD
1) ________ stimulus
2) ____ calcium increase
3) Activation of _________
4) AMPAr ________
5) ________ post synaptic responses
5 steps for LTD
1) Low-frequency stimulus
2) Low calcium increase
3) Activation of protein phosphatases
4) AMPAr internalization
5) Depressed post synaptic responses
What does STDP stand for?
Spike timing-dependent synaptic plasticity
What is the timing mechanism for STDP?
presynaptic neuron activated < 40 ms before postsynaptic –> LTP
postsynaptic neuron neuron activated < 40 ms before presynaptic –> LTD
timing between spikes > 40 ms –> no STDP
6 steps to optogenetics
1) Piece together genetic construct.
2) Insert construct ________.
3. Inject ____ into animal brain; opsin is expressed in targeted neurons.
4. Insert _____, fiber-optic cable plus electrode.
5. Laser light of specific wavelength opens ______ in neurons.
6. Record electrophysiological and behavioral results.
6 steps to optogenetics
1) Piece together genetic construct.
2) Insert construct into virus.
3. Inject virus into animal brain; opsin is expressed in targeted neurons.
4. Insert ‘optrode’, fiber-optic cable plus electrode.
5. Laser light of specific wavelength opens ion channels in neurons.
6. Record electrophysiological and behavioral results.
In the engineering memory experiment, what was the neutral conditioned stimulus (CS), and what was the aversive unconditioned stimulus (US)?
neutral conditioned stimulus (CS) –> tone
aversive unconditioned stimulus (US) –> foot shock
In the engineering a memory experiment, what would indicated memory of the aversive stimulus?
A tone-driven conditioned response (CR, i.e. fear response)
What is the amygdala involved in?
Associative learning, leading to new behavioral and autonomic responses to stimuli that were previously devoid of emotional content.
What was the hypothesis of the engineering a memory experiment?
If LTP of these synapses underlies fear memory, optical induction of LTD should erase memory, and optical induction of LTP should restore memory.
Synapses involved with memory formation are tagged with _____, and they can be induced by the same ______ to undergo LTD or LTP.
Synapses involved with memory formation are tagged with ChR, and they can be induced by the same blue laser to undergo LTD or LTP.
What did LTD induction and LTP induction look like in the ontogenetic portion of the engineering a memory experiment?
LTD induction –> blue laser activation at low frequency prolonged stimulation
LTP induction –> blue laser activation at high frequency bursts
How was ChR used in the engineering a memory experiment?
ChR was expressed in auditory nuclei to label a subset of auditory inputs
In the engineering a memory experiment, LTD ________ the memory formed by ____________. LTP ________ the memory.
