Exam 3~ Chapter 14
Which of the following is true? -- all cells that are activate by the learning experience become engram cells -- cells expressing CREB are most likely to become engram cells -- cell expressing CREB are intrinsically more excitable than cells that do not -- cells expressing CREB inhibit those cells not expressing CREB.
-- cells expressing CREB inhibit those cells not expressing CREB. --cell expressing CREB are intrinsically more excitable than cells that do not -- cells expressing CREB are most likely to become engram cells
The TetTag mouse was an improvement over the sole use of the immediate early gene Arc to tag cells because
-- immediate early gene markers do not persist -- the tag established during learning can persist for many days in the TetTag mouse -- the TetTag mouse permits temporal control over when the tag can occur.
Optogenetic stimulation is critical in the search for engrams because
-- it is critical to tagging neurons -- this method permits the activation of tagged engram neurons that responded to behavioral training
Which of the following is true? -- post-translation processes are sufficient maintain memories -- post-translation processes that build large spines are critical to memory maintenance -- large spines are sufficient to prevent forgetting -- competition for synaptic proteins is usually won by large spines
-- post-translation processes that build large spines are critical to memory maintenance
Which of the following is true? -- post-translation processes are sufficient maintain memories -- post-translation processes that build large spines are critical to memory maintenance -- large spines are sufficient to prevent forgetting -- competition for synaptic proteins is usually won by large spines
-- post-translation processes that build large spines are critical to memory maintenance -- competition for synaptic proteins is usually won by large spines
Memory Retention can be enhanced by
1. blocking NMDA receptors during the retention period 2. preventing AMPA receptor endocytosis
According to the Hardt-Migues experiments
1. enhancing NMDA activity during retention increases the rate of forgetting 2. NMDA receptors bidirectionally regulate forgetting
____ is used to temporally control when a neuron can be tagged
DOX
T/F All neurons activated by the learning experience will become engram cells that support the memory.
False
T/F Enhancing NMDA function during the retention interval prevents forgetting whereas inhibiting NMDA function accelerates forgetting.
False
T/F If a brain lesion of a particular regions disrupts memory storage or retrieval it can be concluded that this region contains engram cells.
False
T/F If following a retrieval test a neuron expresses a marker for an immediate early gene, it can be concluded that this neuron is an engram cell.
False
T/F Karl Lashley invented the term engram?
False
T/F Neurobiologist assume that all forgetting is due to a retrieval failure.
False
T/F Neurons that overexpress CREB are not likely to become engram cells.
False
T/F Regarding the TetTag mouse, if a neuron expresses the marker a time of the behavioral retrieval test then it can be concluded that it is an engram cell.
False
T/F Stress produced by social isolation increases the rate of forgetting because it puts Rac1 in the inactive state.
False
T/F engram cells is deleted this should have no effect on retrieval.
False
Why does PKMζ decrease the rate of forgetting?
It prevent AMPA receptor endocytosis
How was the TetTag mouse an improvement over Guzowski's immediate gene methodology?
It provided temporal control over when cells could be tagged and the fluorescent tagged produced at the time of learning could endure for many days, whereas the immediate early gene tag only lasted a few minutes.
Describe Hebb' concept of a cell-assembly.
Memories are modified connections among neurons.
What would be your conclusion if there was no overlap in the cells tagged by the training experience and those labeled by the retrieval test.
No engram cells were identified.
The dominate negative version of the PKM gene enhances forgetting because it is ________.
Nonfunctional
The study of neural dynamics by Inokuci's group (Gandour et al.) revealed several important discoveries. Describe two.
Not all ensembles activate by the learning experience were activated by the retrieval test. Only ensembles active during sleep became were activated by retrieval.
What should happen during the retrieval test if engram cells are inhibited.
Performance of the test will be impaired.
How did Josselyn demonstrated that neurons that overexpress CREB became engram cells?
She fastened the cells with an inducible diphtheria toxic receptor and after the fear memory was established she administered the diphtheria toxin that selective killed only those cells with the receptor. This treatment eliminated the memory.
Why does the optogenetics method require the use of a viral vector system.
The viral vector system delivers the ChR2 gene.
What is the role of CREB in determining what neurons are selected to become engram cells.
Then intrinsic excitability of neurons expressing CREB is higher than other neurons. This property enables CREB-expressing neurons to out compete the other neurons in the competition for participating in the engram.
Why does GluR23y prevent forgetting?
This peptide prevents AMPA receptor endocytosis.
How was Mayford able to temporally control when neurons in TetTag mouse could be labeled with the fluorescent tag?
This was possible because when Dox was in the drinking water the processes needed to activate the tag were not available. So, the cells could only be labeled with Dox was removed.
In the optogenetics experiment what was the role of the blue light?
To activate neurons expressing ChR2 and theoretically to activate the engram.
In the optogenetics experiment what was the role of DOX?
To temporally control when the ChR2 gene could be expressed.
T/F A retrieval failure can be the result of two similar memories competing for expression.
True
T/F According the results obtained by Migues et al., forgetting can be prevented if the endocytic removal of AMPA receptors is inhibited
True
T/F An advantage of the TetTag mouse is that it permits the temporal control over when a behavioral experience can tag a cell.
True
T/F An engram is the physical basis of a memory.
True
T/F Brain lesions can be considered as a starting point for locating engrams.
True
T/F Enhancing NMDA function during the retention interval produces rapid forgetting.
True
T/F Hebb's concept of a cell assembly is still generally accepted as correct?
True
T/F If following a retrieval test a neuron expresses a marker for an immediate early gene and the fluorescent marker, it can be concluded that this neuron is an engram cell.
True
T/F Immediate early genes can serve as markers or tags for neuron activated by a behavioral experience.
True
T/F In order to conclude that a set of neurons are engrams, these neurons must be active both by the learning event and by the retrieval test.
True
T/F Inhibition of either NMDA receptors or voltage-dependent calcium channels (vdCCs) can prevent the for- getting of an object-location memory.
True
T/F Neurons that overexpress CREB win in the competition for becoming engram cells because their intrinsic excitability is increased.
True
T/F Neurons that overexpress CREB win in the competition for becoming engram cells.
True
T/F Optogenetics provides a methodology for testing the requirement that the activation of engrams must activate the behavioral measure of the memory.
True
T/F Richard Simon invented the term engram?
True
T/F Simon's term ecphory is another word for engram.
True
T/F Stress produced by social isolation increases the rate of forgetting because it puts Rac1 in the active state.
True
T/F The consolidation period ends when the memory trace is no longer vulnerable to the disruption of ZIP.
True
T/F The consolidation period ends when the memory trace is no longer vulnerable to the disruption of transcription and translation processes.
True
T/F The peptide GluR23y inhibits the removal AMPA receptors from the PSD.
True
T/F The term ecphory is roughly equivalent to the term retrieval.
True
From the perspective of the brain, processes that produce active forgetting may have evolved to help maintain the________ of excitatory and inhibitory inputs on a neuron.
balance
If engram cells are inhibited at the time of retrieval the test performance will be ______.
impaired
The increased excitability of CREB expressing neurons enables them to _______
inhibit
Neurons that ________ CREB win in the competition for becoming engram cells
overexpress
In order to conclude that a neuron is an engram cell it must be activated by the learning experience and by ________.
retrieval
Neuronal sub-ensembles activated by the learning experience but not replayed during sleep ________ become engram assembles.
will not
