Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NSCI 200 - Intro to Neuroscience 1 > Lecture 13 - Synaptic Plasticity I > Flashcards

Lecture 13 - Synaptic Plasticity I Flashcards

1
Q

What does glutamate uncaging causing LTP indicate about the nature of LTP?

A

Since glutamate uncaging activates postsynaptic glutamate receptors without the involvement of the presynaptic cell, uncaging causing LTP indicates that LTP is a postsynaptic phenomenon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

True or False?:

LTP requires a rise in postsynaptic potassium.

A

False

LTP requires a rise in postsynaptic calcium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens to an inactive synapse when another synapse on the same postsynaptic cell is given a strong stimulation (tetanus)? What is this trait called?

A

The inactive synapse is not strengthened. This is called specificity. The strengthening of the stimulated synapse is specific to just that synapse.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

True or False?:

Weak but prolong stimuli can cause heterosynaptic LTD.

A

False

Weak but prolong stimuli can cause homosynaptic LTD.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to long-LTP (L-LTP) if protein synthesis is inhibited? Does the same happen for LTP?

A

If protein synthesis is blocked, L-LTP will degrade over time (relative to a control) because there will not be enough protein available to enlarge the spine and add more AMPARs. This does not happen for LTP because it isn’t as long and uses proteins already present in the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens to a synapse when it is weakly stimulated at the same time that another synapse on the same postsynaptic cell is given a strong stimulation (tetanus)? What is this trait called?

A

The weakly stimulated synapse will be strengthened. This is called associativity. Since the inputs are activated together, they will both strengthen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

LTP and LTD are both dependent on an influx of Ca2+. Why does calcium trigger protein phosphatases in LTD to reduce the amount of AMPARs while it triggers CaMKII in LTP to increase the amount of AMPARs?

A

Protein phosphatases have a high calcium affinity and protein kinases (CaMKII) have a low calcium affinity. When there is a low amount of calcium, more is bound by the high affinity phosphatases than the low affinity kinases. When there is a high amount of calcium, the low affinity kinases are able to bind at a rate higher than that of the phosphatases. As such, LTD facilitates a low intracellular calcium concentration while LTP facilitates a high intracellular calcium concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True or False?:

The pairing of pre-synaptic activity with direct post-synaptic depolarization will induce LTP.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What happens when you stimulate the Schaffer Collateral-CA1 synapse after tetanus relative to before tetanus? What is this called?

A

After tetanus, it becomes more depolarized than before tetanus. This is called long-term potentiation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the most studied synapse in the brain? Why?

A

CA3(/Schaffer Collaterals) to CA1 (in the Hippocampus)

It is one of the most studied because of its accessibility, but mostly because it is thought to be a key structure for memory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the distinct temporal phases of LTP?

A
  • Insertion of more AMPARs
  • Local synthesis of dendritic mRNAs
  • CREB dependent transcription
  • Growth of spines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

True or False?:

LPT occurs at synapses on spines.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What did Hebb postulate?

A

“When an axon of cell A… excite[s] cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells so that A’s efficiency as one of the cells firing B is increased.”

(Neurons that fire together wire together.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What did Stent’s extension of Hebb’s Postulate state?

A

“Neural connections weaken when they are inactive at the same time that the postsynaptic neuron is active or will weaken if they are active but consitently fail to cause the cell to fire an action potential.”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens when you shine UV light on caged glutamate?

A

Glutamate separates from the rest of the cage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens to long-term potentiation if NMDARs are blocked?

A

LTP will not occur. The initial spike seen in the graph on the right is due to PTP.

17
Q

What changes to the long-term change to synaptic strength when the amount of NMDA receptor activation increases?

A

LTD will occur at low NMDA activation, but as you increase it, LTP will occur.

18
Q

What happens to LTP when CaMKII autophosphorylation is blocked?

A

There is a brief increase but it is not long-lasting.

19
Q

What do motor learning and novel sensory experiences lead to in mice?

A

Motor learning and novel sensory experiences promote rapid dendritic spine formation.

20
Q

What are the two types of long-term depression? How does each happen?

A

Heterosynaptic - Synapse is weakened because it is inactive when the neuron is active.

Homosynaptic - Synapse is weakened because it is active but fails to cause the cell to fire an action potential.

21
Q

What is the benefit of using 2-photon excitation microscopy instead of 1-photon excitation microscopy?

A

2-photon results in fluorescens from the focal spot only while 1-photon will have fluorescence in out of focus planes.

22
Q

What are the characteristics of long-term potentiation that are expected for memory?

A
  • Persistence - Is maintained for a long time following a rapid induction.
  • Input Specificity - Induced only at appropriately stimulated synapses, and not neighbouring unstimulated synapses.
  • Associativity - Inputs activated together will strengthen.
23
Q

How does botox inhibit LTP?

A

Botox interferes with vesicle fusing by damaging the SNARE proteins. The AMPARs that are moved to the synaptic membrane to cause LTP are stored on vesicles. As such, botox inhibits more AMPARs from being added to the synapse.

24
Q

True or False?:

L-LTP requires CREB activation and dendritic protein synthesis.

A

True

25
Q

True or False?:

LTP leads to the inesertion of more NMDARs.

A

False

LTP leads to the insertion of more AMPARs.

26
Q

What type of synapses were used to prove that LTP leads to the insertion of AMPARs?

A

Silent Synapses (Synapses with NMDARs but without AMPARs)

27
Q

How can you activate glutamate receptors in a specific synapse?

A

You can activate glutamate receptors in a specific synapse by uncaging caged glutamate using 2-photon excitation microscopy.

28
Q

What happens to AMPARs in LTD?

A

Calcium binds with protein phosphatases which dephosphorylates target proteins (responsible for the addition/removal of AMPARs), resulting in AMPARs’ endocytosis back into the cell.

29
Q

Which part of the brain is studied for plasticity research?

A

Hippocampus

30
Q

True or False?:

LTP and LTD require NMDAR activation, Ca2+ influx, and CaMKII.

A

False

LTP and LTD both require NMDAR activation and Ca2+ influx. LTP needs CaMKII while LTD needs proteins phosphatases..

31
Q

How are spine heads affected by LTP?

A

Spine heads enlarge during LTP.

32
Q

Which kinase does LTP require the activation of?

A

CaMKII

33
Q

True or False?:

Immature synapses start silent and strengthen over time.

A

True

34
Q

What happened to H.M. that made him one of the most famous patients in neuroscience?

A

In 1953, H.M. had a bilateral removal of his hippocampi and medial temporal lobes to treat severe epilepsy. As a result of that, he could not form new declarative memories.

35
Q

Why is long-term synaptic plasticity important?

A

Synaptic plasticity is required during development such that stable and appropriate neural connections can be made. Experience-dependent modifications in synaptic transmission are thought to occur during learning and underlie the storage of memories.

36
Q

True or False?:

H.M. was able to form emotional memories. For example, he remembered to dislike a doctor that poked him with a pin when they shook hands.

A

True

NSCI 200 - Intro to Neuroscience 1 (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions