Deck 4: Stabilizing Long-Term Potentiation

Question 1

Application of a low-frequency stimulus within a day after the TBS-inducing stimulus is sufficient to interrupt the development of a long-lasting LTP.

Answer 1

False

Question 2

Low-frequency stimulation delivered 15 minutes after LTP induction has no effect on stabilization

Answer 2

True

Question 3

When cofilin is phosphorylated, F-actin is more likely to remain in its filament state.

Answer 3

True

Question 4

Applying drugs that inhibit myosin IIb prior to TBS prevents the induction and stabilization of LTP.

Question 5

When cofilin is phosphorylated actin polymerization is prevented.

Question 6

Neural cadherins can exist as either monomers or cis-stranded dimers, with equal adhesive properties.

Question 7

Neutralizing the response of β integrins to extracellular ligands prevents enduring LTP normally produced by TBS, but it has no effect on the initial induction of LTP.

Question 8

Large spines endure longer than small spines.

Question 9

When cofilin is phosphorylated actin polymerization is prevented.

Question 10

Drugs like latrunculin and cytochalasin prevent actin polymerization.

Question 11

In it nonactive state CaMKII bundles active filament.

Question 12

In its non-phosphorylated state cofilin can sever actin filaments.

Question 13

When actin polymerization is inhibited the actin cytoskeleton will enlarge.

Question 14

Inhibiting NMDA receptors will prevent spine enlargement.

Question 15

Stabilization of LTP depends on the regulation of actin dynamics.

Question 16

The generation but not the stabilization of LTP depends on the reorganization of N-cadherins.

Question 17

The stabilization of LTP depends on the reorganization of N-cadherins, but the generation of it does not.

Question 18

Applying latrunculin and cytochalasin to the LTP slice 15 minutes following induction has no effect on LTP stabilization.

Question 19

The delivery of low-frequency stimulation prior to induction of LTP has no effect on its generation but prevents LTP stabilization.

Question 20

Explain the observation that people with amnesia resulting from an accident often can recall events that took place long ago but not events that occurred within minutes of the accident?

Question 21

How can a weak stimulus (low frequency) be used to prevent the development of a long-lasting LTP?

Question 22

What is a benefit of larger spines?

Question 23

Identify a role for inactive CaMKII.

Question 24

Why is non-phosphorylated cofilin important to the subsequent enlargement of the spine?

Question 25

What is the role of LIMK in the stabilization of LTP?

Question 26

In Harou Kasai's study of single spine enlargement, what was the effect of antagonizing NMDA receptors?

Question 27

In Harou Kasai's study of single spine enlargement, what was the effect of the actin polymerization inhibitor, latrunculin

Question 28

The severing properties of cofilin are initially important to stabilization. However, it is important that this function be terminated. How does this normally happen?

Question 29

The severing properties of cofilin are initially important to stabilization. However, it is important this this function be terminated. Why?

Question 30

Describe how actin filaments are broken down into smaller units. Why is this beneficial?

Question 31

What is an "adhesive zipper"?

Question 32

Briefly describe how the delivery of low-frequency stimulation prior to induction of LTP affects its generation and its stabilization.

Question 33

The state of cofilin regulates _______ polymerization and depolymerization.

Question 34

Inhibiting the activity of myosin IIb prevents enduring _______ but has no effect on its _______.

Question 35

The Rho-ROCK GTPase pathway phosphorylates _______.

Question 36

In its active state, LIMK _______ cofilin.

Question 37

When in a phosphorylated state, cofilin no longer _______ F-actin.

Question 38

_______ phosphorylates cofilin.

Question 39

If NMDA receptors are inhibited, caged glutamate will prevent _______.

Question 40

In its inactive state CaMKII _______ actin filaments.

Question 41

In its normal non-phosphorylated state, cofilin _______. (Select all that apply.)

A) bundles actin.
B) severs actin.
C) reorganizes actin.
D) crosslinks actin.
E) prevents actin polymerization

Question 42

Which statement(s) is/are true? (Select all that apply.)

A) Actin can exist as both a monomer and a polymer.
B) In a phosphorylated state cofilin severs actin filament.
C) The kinase LIMK phosphorylates cofilin.
D) In a phosphorylated state cofilin permits actin polymerization.
E) None of the above

Question 43

Which statement(s) support(s) the hypothesis that actin polymerization is critical to stabilizing LTP? (Select all that apply.)

A) Low-frequency stimulation following LTP induction prevents LTP from enduring.
B) Inhibiting NMDA receptors prevents LTP from enduring.
C) Inhibiting actin polymerization about 15 minutes following LTP induction prevents LTP from enduring.
D) Inhibiting actin polymerization prior to LTP induction does not prevent the generation of LTP.
E) None of the above

Question 44

Which of the following observations were revealed by single spine imaging studies? (Select all that apply.)

A) The protein composition of single spines rapidly changes in response to glutamate.
B) Inhibiting polymerization prevents initial spine enlargement.
C) Proteins known to stabilize actin initially vacate the spine.
D) Spines did remain enlarged if cofilin was not phosphorylated.
E) None of the above

Question 45

Which action(s) influence(s) LTP stabilization but not induction? (Select all that apply.)

A) Applying drugs that inhibit myosin IIb prior to TBS
B) Inactivation of the kinase LIMK
C) Phosphorylating cofilin
D) Preventing N-cadherin dimerization
E) None of the above