Ch. 12: Memory Modulation Systems

Question 1

Why are arousing experiences memorable? (Central Idea)

Answer 1

Arousing events activate neural and hormonal processes that influence the cellular-molecular processes that consolidate memory

Question 2

What are the two independent effects of experience?

Answer 2

-It can initiate the acquisition and storage of memory trace
-It can activate the release of adrenal hormones that can modify the processes that store memory

Question 4

True or False: Memory modulators have long-time role and a influence on the storage of long-term memory

Answer 4

False: Memory modulators have a time-limited role and influence only the storage of very recently acquired memories. They operate during a period of time shortly after the behavioral experience when the memory trace is being consolidated

Question 5

When do memory modulators operate?

Answer 5

Operate during a period of time shortly after the behavioral experience when the memory trace is being consolidated

Question 5

True or False: The amygdala is in a position to influence or modulate storage processes in other regions of the brains

Answer 5

True, it is anatomically connected to many regions of the brain that are likely storage sites for different types of memories

Question 6

Why does the state of arousal generated by the behavioral experiences influences memory strength?

Answer 6

Arousing stimuli can stimulate the adrenal gland, specifically the adrenal medulla, to secrete a hormone or molecule into blood stream called epinephrine

Question 7

What is epinephrine’s second effect?

Answer 7

It can influence the strength of a memory trace

Question 8

Where does epinephrine come from?

Answer 8

Secreted by the adrenal medulla

Question 9

What does epinephrine bind to?

Answer 9

receptors called adrenergic receptors

Question 10

What is thought to be the primary mediator of epinephrine’s influence on memory?

Answer 10

Basolateral Amygdala (BLA)

Question 11

True or False: A rat can learn the Morris water escape task even when the amygdala is damaged

Answer 11

True: Shows that the amygdala is not a critical storage site for these memories

Question 12

True or false:
The amygdala facilitates the storage of memories but is not needed to retain the memory

Answer 12

True

Question 13

What happens if we inject amphetamine into the amygdala after morris water escape task training?

Answer 13

Retention performance on both versions of the task is enhanced

Question 14

True or False: The hippocampus is thought to be critical storage site for place learning

Answer 14

True

Question 15

What happens when you inject lidocaine into the basal nucleus (A certain section) of the basolateral amygdala?

Answer 15

Following avoidance training the retention of the inhibitory avoidance response is impaired

Question 16

True or False the amygdala is a unitary structure

Answer 16

False: It is not, it consists of many subnuclei (a cluster of neuron cell bodies (grey matter) in the central nervous system that typically shares a general function.)

Question 17

What can lidocaine do?

Answer 17

Temporarily suppress neural activity

Question 18

What happens when lidocaine is injected into the Central nucleus of the amygdala?

Answer 18

No effect on retention, this data establishs that the BLA is likely the major brain region mediating the effects of epinephrine

Question 19

True or False: Rats that were given epinephrine (That would naturally be released by the adrenal gland) displayed enhanced inhibitory avoidance

Answer 19

True: the enhancing effect of epinephrine was time dependent, the more effective when it was given shortly after the training trial

Question 20

True or False Epinephrine crosses the blood brain barrier

Answer 20

Epinephrine does not cross the blood-brain barrier, when it is released from the adrenal medulla it binds to adrenergic receptors on the vagal nerve, in response to the activation, the vagal nerve releases glutamate on neurons in the solitary tract nucleus

Question 21

If epinephrine cant cross the blood-brain barrier then how does it effect the brain?

Answer 21

Bind to adrenergic receptor on the vagal nerve, which then releases glutamate one neurons in the solitary tract nucleus (which then release glutamate onto neurons in the locus coeruleus which in turn release norepinephrine in the BLA)

Question 22

What is the vagal nerve?

Answer 22

The nerve that holds the adrenergic receptors that are triggered by epinephrine. In response to activation the vagal nerve releases glutamate one neurons in the solitary tract nucleus

Question 23

What happens after the vagal nerve activates the NTS (solitary tract nucleus) ?

Answer 23

The neurons release glutamate onto neurons in the locus coeruleus which in turn release norepinephrine that binds to the adrenergic receptors in the BLA

Question 24

What do the neurons in the locus coeruleus do?

Answer 24

Get activated by NTS and then release norepinephrine that binds to the adrenergic receptors in the BLA

Question 25

why cant epinephrine molecules cross the blood-brain barrier?

Answer 25

Too big

Question 26

What does Microdialysis allow for?

Answer 26

Allows extracellular fluid to be collected from deep within the brain

Question 27

Why do we want to implant a microdialysis probe into a rat brain?

Answer 27

To be able to collect extracellular fluid while the rat is freely moving. The content of this fluid can then be analyzed for its composition

Question 28

What was the micro dialysis methodology used to do?

Answer 28

Was used to extract norepinephrine from the extracellular brain fluid

Question 29

what happened to the level of norepinephrine released into the extracellular fluid in inhibitory avoidance training?

Answer 29

It wad dependent on the intensity of the shock, the intensity of shock = intensity of norepinephrine

Question 30

what is required to increase the level of norepinephrine?

Answer 30

Shocking the rat and allowing it to explore the avoidance training apparatus

Question 31

What happened when we injected norepinephrine into the amygdala after place learning?

Answer 31

Enhanced the rat's retention of the platform location

Question 32

what happened when we injected propranolol (beta-adrenergic receptor antagonist)?

Answer 32

Retention of the platform location in the morris water test was impaired

Question 33

What happened when we injected norepinephrine into the amygdala following inhibitory avoidance training?

Answer 33

The rat had enhanced retention performance

Question 34

What happens if we inject propranolol into the amygdala following inhibitory avoidance training?

Answer 34

The rat had impaired retention

Question 35

What are the five steps to the ARC translation experimental design?

Answer 35

1. Cannula implanted into amygdala 2. Rats trained on the Inhibitory Avoidance task (shocked) 3. Rats injected with either a b-adrenergic agonist (increases arousal) or lidocaine which inactivates the BLA neurons 4. Rats either sacrificed or tested on the inhibitory avoidance task 5. Hippocampus brain tissue was sample for Arc Protein

Question 36

What does lidocaine do to the level of Arc protein in the hippocampus?

Answer 36

Lidocaine reduces the level of arc protein and decreases inhibitory avoidance learning

Question 37

What does clenbuterol (increases arousal) do to Arc protein?

Answer 37

It increases the level of Arc protein and enhances the inhibitory avoidance learning

Question 38

How does BLA modulate memory? (Based on the findings of the Arc translation experiment)

Answer 38

the BLA might modulate memory by influencing the level of Arc protein in the hippocampus

Question 39

What happens when norepinephrine is released into the hippocampus?

Answer 39

PKA is activated and it phosphorylates two sites of the GluA1 AMPA receptor subunit, this allows the trafficking of GluA1s into the dendritic spine and increases memory strength

Question 40

When PKA phosphorylates two sites on the GluA1 AMPA receptor subunit what happens?

Answer 40

It allows for the trafficking of GluA1s into the dendric spine and increase memory strength

Question 41

What is bioenergetics?

Answer 41

The flow of energy in cells. the primary source of energy is glucose

Question 42

Where does glucose enter the brain?

Answer 42

via the cerebral vasculature

Question 43

What does an arousing event do to the adrenal medullar?

Answer 43

Activates the adrenal medulla to release epinephrine into the blood system, where it binds to adrenergic receptors in the liver cells, this results in the liver secreting glucose into the blood where it enters the brain via the cerebral vasculature system

Question 44

Explain the livers influence on the brain:

Answer 44

Epinephrine binds to adrenergic receptors in the liver cells, this results in the liver secreting glucose into the blood where it enters the brain via the cerebral vasculature system

Question 45

True or false: epinephrine modulates memory by binding to adrenergic receptors on the liver cells causing them to release glucose

Answer 45

True

Question 46

what is the difference between old and young rats livers?

Answer 46

Only young rats livers secrete glucose even if epinephrine is released by the adrenal gland in both old and young rats

Question 47

what happens when you inject glucose into old rats?

Answer 47

A systemic injection of glucose prevents forgetting in old rats tested 7 days after inhibitory avoidance training

Question 48

True or false: Avoidance training does not lead to CREB phosphorylation in old rats

Answer 48

True, if glucose is injected following training, phosphorylated CREB is detected

Question 49

What does Dexamethasone do?

Answer 49

when it is injected systemically following inhibitory avoidance training, it enhances retention

Question 50

True or False: Propranolol prevents dexamethoazone from enhancing retention

Answer 50

True: The effect of dexamethasone also depends on epinephrine being released in the amygdala