NRSC4032 - Chapter 15: The Fate of Retrieved Memories

What is the fundamental difference between reconsolidation theory and active trace theory?

Reconsolidation theory says that the act of retrieval is enough, itself, to disrupt an already established memory, whereas active memory trace theory says that retrieval makes a consolidated memory vulnerable to disruption due to other agents.

According to Lewis all _______ memory traces are vulnerable to disruption

active

Inhibiting proteasome activity in the basolateral amygdala can protect memories from the effect of __________.

anisomycin

(T/F) inhibiting AMPA receptors should prevent memory destabilization.

false

If the proteasome is_______ repetition will not strengthen the memory.

inhibited

According to the state-dependent learning view _______ state present at the time of a learning experience become part of the engram and need to be present in order to retrieve the memory.

internal

A brief reminder cue is sometimes called _______treatment.

reactivation

List the key events that destabilize the synaptic basis of a memory trace, starting with glutamate release.

1) Glutamate release; 2) increase in calcium levels via NMDA receptors and vdCCs; 3) ubiquitination of scaffolding proteins and activation of CaMKII; 4) proteasomes are phosphorylated and translocated to the spine; 5) degradation of scaffolding proteins; 6) endocytosis of AMPA receptors; 7) de-potentiation of the synapse.

(T/F) A prediction error occurs when the information contained in the retrieved memory does not match the information contained in the test environment.

true

(T/F) According to Lewis's active memory theory, remembering an old, consolidated memory will return it to an active state and make vulnerable to disruption.

true

(T/F) According to Lewis's active trace theory, both very new memories and retrieved memories are vulnerable to disruption.

true

(T/F) According to integration theory the amnesia produced when drugs like anisomycin are given after the memory is retrieved is due to a retrieval failure.

true

(T/F) According to reconsolidation theory, retrieving a consolidated memory can unbind or destabilize the supporting synapses.

true

(T/F) According to the state-dependent learning view internal states present at the time of a learning experience become part of the engram and need to be present in order to retrieve the memory.

true

(T/F) Anisomycin's effects on retrieved memory depend on proteasome activity.

true

(T/F) Blocking the proteasome can prevent the need for reconsolidation.

true

(T/F) Cue dependent amnesia refers to when retrieving a memory returns it into a labile state that made it vulnerable to disruption.

true

(T/F) Destabilization of the memory trace is mediated by the ubiquitin proteasome system.

true

(T/F) Erasing drug associate memories can prevent cravings and relapse.

true

(T/F) Erasing memories that associate environmental cues with taking a drug, such as cocaine, can prevent cravings and relapse.

true

(T/F) If either NMDA receptors and vdCCs are antagonized or the UPS system is inhibited, anisomycin will have no effect the reactivated memory trace.

true

(T/F) In order for repetition to strengthen the memory, the established trace must be destabilized.

true

(T/F) Inhibiting AMPA receptors impairs the retrieval of the memory but does not prevent its destabilization.

true

(T/F) Inhibiting NMDA receptors does not impair the retrieval of the memory but does not prevent its destabilization.

true

(T/F) Lewis discovered that reactivated memories are vulnerable to disruption by ECS

true

(T/F) Memories are destabilized when their retrieval memory returns them to a state of vulnerability.

true

(T/F) Nader discovered that when injected into the BLA following a reactivation treatment, anisomycin had no effect on the short-term memory test but produced a large impairment on the long-term memory test.

true

(T/F) Rats that received ECS and reactivation were impaired.

true

(T/F) Rats that received ECS only were not impaired.

true

(T/F) The brain treats a reactivated memory as a novel experience, so it is modified/updated according to the new context.

true

(T/F) The encoding specificity principle asserts that that successful memory retrieval depends on a match between the retrieval cues and the environmental stimulation encoded into the engram.

true

(T/F) The memory strengthening effect of repetition can be prevented by inhibiting the AMPA receptors.

true

(T/F) anisomycin prevents reconsolidation of the memory trace.

true

(T/F) inhibiting NMDA receptors or the proteasome should prevent destabilization.

true

(T/F) trace destabilization enhances the effect of repetition on memory

true

(T/F) trace destabilization opens a temporal window during which the trace can be modified

true

Why should inhibiting the proteasome prevent anisomycin from impairing the memory for a retrieved memory.

Because it prevents the degradation of the key scaffolding proteins that keep AMPA receptors in the PSD. So the no new protein is needed

(T/F) βlac which inhibits proteasome activity prevents destabilization

true

According to reconsolidation theory, retrieving a consolidated memory can ______ the supporting synapses.

unbind or destabilize

According to reconsolidation theory, retrieval

weakens synaptic connections, initiates new protein synthesis, and can disrupt consolidated memories

What is cue-dependent amnesia?

when retrieving a memory returns it into a labile state and makes it vulnerable to disruption.

(T/F) Lewis discovered that all memories are vulnerable to disruption by ECS.

false

(T/F) Only novel experiences generate active memory traces.

false

(T/F) Retrieving a memory depends on AMPA receptors.

false

(T/F) Retrieving a memory depends on NMDA receptors.

false

(T/F) Retrieving or reactivating the memory always makes it stronger.

false

(T/F) The age of a memory trace is the only determinant of its vulnerability.

false

According to the active state theory, there are two ways a memory trace can be put into the short-term active state. What are they?

1) Novel experiences generate new active memory traces 2) Retrieving or reactivating existing long-term memory traces will return these traces to the short-term active state.

In the original Lewis reactivation experiment there were four training conditions. What were they?

1) Rats that received ECS following reactivation 2) rats that received no ECS following reactivation 3) rats that received no reactivation but did receive ECS 4) rats that received neither reactivation nor ECS.

Retrieving a memory depends on _____receptors.

AMPA

What is the role of anisomycin in reconsolidation theory?

In reconsolidation theory, it prevents the new round of protein synthesis needed to reconsolidate the memory

How does reactivating a memory destabilize the synapses associated with that memory?

Increased calcium levels activate the UPS system, which degrades key scaffolding proteins, and thus there is a decrease in the surface levels of AMPA receptors.

Destabilize a memory trace depends on ______receptors.

NMDA

Does anisomycin have any effect on retrieved memories when the proteasome system is inhibited? Why is this finding important?

No. It reveals how retrieval causes disruption; it shows that if scaffolding proteins were not degraded in the first place, the trace would be intact and new protein synthesis would not be necessary to maintain it.

Active trace theory assumes that

a retrieval cue can return the memory to an active state, memories in the active state are vulnerable to disrupt, and memories in an active state will become inactive

Cue dependent amnesia occurs when

a retrieved memory is followed by a disrupting event

If NMDA, CaMKII, or proteasome are inhibited the memory trace should not______.

destabilize

If the proteasome is inhibited the memory trace should not _________.

destabilize

Some reasons for drug relapse are

drug associated cues can evoke strong urges to take drugs, cues present when drugs are taking become associated with drug consequences, addiction treatments fail to eliminate the ability of drug cues to evoke urges, and drug seeking behavior is elicited by drug associated cues

Exposure to __________ can cause a treated drug user to relapse.

drug related cues

To explain cue-dependent amnesia produced by anisomycin integration theory assumes that

drugs produce internal state cues, retrieval is best when the retrieval cues match the stimuli present at the time of training, cue-dependent amnesia is due to a retrieval failure, and internal state cues produce by drug become part of the retrieval cue complex

(T/F) Inhibiting AMPA receptors impairs the retrieval of the memory and its destabilization.

false

(T/F) Inhibiting NMDA receptors impairs the retrieval of the memory and its destabilization.

false

__________ associated with drugs are one important contributor to relapse.

environmental cues

(T/F) According to active trace theory, retrieving a consolidated memory is enough to disrupt it.

false

(T/F) According to integration theory the amnesia produce when drugs like anisomycin are given after the memory is retrieved is due to a storage failure.

false

(T/F) According to the encoding-specificity principle the absence of critical retrieval cues will enhance memory retrieval.

false

(T/F) Cue dependent amnesia refers to the forgetting induced by the retrieval of another memory.

false

(T/F) Cues associated with taking drugs are irrelevant to drug-addiction relapse.

false

(T/F) If the information contained in the retrieved memory matches the information contained in the test environment the memory trace will be destabilized.

false

According to the state-dependent learning hypothesis memory recall will be ______if internal state cues produce by a drug (such as anisomycin) following memory reactivation are not present at the time of retrieval.

impaired

A retrieved memory trace is restabilized by __________.

new protein synthesis

Inhibiting CaMKII should ______ destabilization.

prevent

According to integration theory the amnesia produced when drugs are administer following a memory reactivation treatment is due to a ______ failure.

retrieval

Cue dependent amnesia refers to when _____ a memory returns it into a labile state that made it vulnerable to disruption.

retrieving

What was Don Lewis' major discovery?

that reactivated memories are vulnerable to the disrupting effect of ECS

If the proteasome is inhibited just prior to memory reactivation the retrieved memory

the memory trace will not be destabilized