Chapt. 12 - Memory Modulation

Question 1

If you don’t have a ____ you won’t have memory modulation

Answer 1

amygdala

Question 2

Why are arousing experiences memorable

Answer 2

arousing events activate the neural and hormonal processes the influence the cellular-molecular processes that consolidate memory
emotional experiences encode AND activate systems that impact consolidation

Question 3

Explain the memory modulation framework (specifically the independent effects of experience)

Answer 3

(James McGaugh)
experience has two independent effects.
1. it can initiate acquisition and storage of the memory tract
2. and it can activate the release of adrenal hormones that can modulate the processes that store the memory

Question 4

Memory modulators

Answer 4

the hormones and other neural systems that are not part of the storage system of memory but they influence the synapses that store the memory.
they have a time-limited role, they can only influence storage of very recently acquired memories, usually few hours to improve of impair the representation

Question 5

Huston memory modulation experiment

Answer 5

trained mice on passive (dont move and be good) avoidance task, where animals shocked if stepped down. some mice were fed in their home cages immediately after stepping down and receiving a shock –> these mice remained on the platform longer than those that did no get fed, enhancing memory and performing better.
food modulated memory, because was in a timeline where could be modulated

Question 6

What is memory consolidation

Answer 6

(muller and pilzecker)
hypothetical process by which the labile (easily changeable) neural representation of a memory that exists immediately after is it formed, changes over time into a relatively permanent representation

Question 7

Post training events can ___ consolidation processes while others can ____ the process

Answer 7

disrupt
enhance
(events during the labile period can have these effects)

Question 8

What is considered the great modulator of memories and why

Answer 8

The basolateral amygdala because it is anatomically connected to many brain regions that are storage sites for different memories. It is in a position to influence and modulate storage processes in other regions of the brain.
The amygdala itself is not a STORAGE SITE

Question 9

Results of place learning water task with injection of amphetamine into basolateral amygdala

Answer 9

injected at a specific time (treatment of immediately after or 6 hours after training) the immediately after improved retention performance
hippocampus thought to be critical storage site for this task

Question 10

Results of injected amphetamine into basolateral amygdala following training of visible platform task

Answer 10

improved retention (short latency means better retention)
dorsal striatum thought to be critical for this

Question 11

Explain post training memory improvement paradigm

Answer 11

second day of training, give injections. post training with amphetamine, next day is drug free and they do significantly better.

Question 12

Lidocaines effect on retention depends on…
Explain!

Answer 12

where it is injected
lidocaine temporarily shuts down whatever system is it injected into and impairs it (longer the latency the better the memory)
1. injection into basal nucleus of basolateral amygdala after avoidance training, impaired retention of the inhibitory avoidance response
2. injection into central nucleus of amygdala had no effect (because not actually part of memory modulation)

Question 13

Adrenal glands and composed of what two parts

Answer 13

endocrine gland located above the kidney
1. adrenal medulla - secretes epinephrine
2. adrenal cortex - secretes glucocorticoids

Question 14

____ that is released by the adrenal ____ plays a major role in memory modulation processes

Answer 14

epinephrine
medulla

Question 15

problem with epinephrine molecules

Answer 15

they are too large in the blood to cross the blood brain barrier so need to find a different way to influence the amygdala.

Question 16

What are the ways that epinephrine molecules are able to influence the amygdala

Answer 16

because too large to cross the blood/brain barrier
use parallel processes of the cranial nerve and the liver

Question 17

Epinephrine uses the cranial nerves to send information about the body to the brain by…

Answer 17

the vagus nerve arises from the medulla supplying the internal organs (viscera) of the thoracic and abdominal cavities

Question 18

Epinephrine enhances memory for inhibitory avoidance training experiment

Answer 18

rats receive mild shock when cross into dark side of the room. control receives vehicle, and treatment is injected with dose of epinephrine - dose is to mimic the level released if an animal experienced a strong shock. Treatment showed improved response (increased latency), but was time dependent/ ex. effects didn’t last over 30 mins to be affective

Question 19

Explain the Epinephrine and Vagus connection

Answer 19

epinephrine when released from the medulla, binds to adrenergic receptors of the vagal nerve. If activated, vagal nerve releases glutamate on neurons in the solitary tract nucleus (NTS).
the activated NTS neurons release glutamate in the locus coeruleus, which release norepinephrine that binds to adrenergic receptors in the basolateral amygdala.
disrupting any component will prevent arousal of enhancing memory

Question 20

Microdialysis allows…

Answer 20

extracellular fluid to be collected from deep within the brain
1. rat implanted microdialysis probe in the brain
2. freely moving rat connected to instrumentation designed to extract small quantity of extracellular fluid and other content and then analyzed for its composition
(want to see if norepinephrine is released)

Question 21

microdialysis used to extract norepinephrine from the extracellular brain fluid and found 3 things

Answer 21

1. level of norepinephrine released in fluid in inhibitory avoidance training is determined by the intensity of the shock
2. just shocking a rat or allowing it to explore does not increase level of norepinephrine
3. requires the rat to both explore and be shocked

Question 22

Norepinephrine injected in amygdala improves retention performance

Answer 22

inject after place learning, enhances rats retention of the platform location or inject propranolol to block learning and impair.
NE injected after weak shock (enhanced)
Propranolol injected after strong shock (impaired)

Question 23

Experiment to see what does the amygdala signal do (arc translation experiment DESIGN)

Answer 23

insert tube used to administrate medicine
rats trained on inhibitory avoidance task
either injected with b-andrenergic agonist (help) or lidocaine (shut down)
rats either sacrificed or tests on task
hippocampus brain tissue was sample for arc protein

Question 24

Results of arc translation experiment/ amygdala signal

Answer 24

the arc protein is important for long term retention and there are opposite effects of enhancing (b-andrenergic agonsit) or lidocaine (shut down/reduce levels of arc protein) on inhibitory avoidance learning

Question 25

Define bioenergetics and the source of energy is

Answer 25

the flow of energy in cells and the primary source of energy is glucose which enters the brain via the cerebral vasculature.

Question 26

epinephrine modulates memory by

Answer 26

binding to adrenergic receptors on the liver cells causing them to release glucose

Question 27

Response to foot shock, _____ releases epinephrine in both young and old rats while in the liver of only ____ rats secrete glucose

Answer 27

adrenal gland
young

Question 28

Only ___ rats show increase in shock intensity because of the increase in glucose

Answer 28

young (because also secrete in liver)

Question 29

What four experiments did Mcdonald perform to test amygdala being crucial modulator of memory

Answer 29

1. water maze
2. long term retention
3. one trail place learning
4. post training memory improvement

Question 30

Water task to show amygdala is crucial modulator of memory

Answer 30

no impact on water task with impaired amygdala
(head direction, path length, or latency)

Question 31

Long term retention to show amygdala is crucial modulator of memory

Answer 31

24 hour retention, bring them back after 24 hours
no difference in heading angle or quadrant preference.

unusual that they still show strong representation without amygdala after 30 days but technically still works

Question 32

One trail place learning to support that amygdala is crucial memory modulator

Answer 32

find new place every day
no difference with or without amygdala (place control is highly dependent on the hippocampus)

Question 33

Retention place learning to support that amygdala is crucial memory modulator

Answer 33

go for first swim, taken back to homes, then 24 hours later taken for their second swim
no difference between groups! (path length, head direction, latency)

Question 34

____ injection had the best post training memory modulation of the water maze task

Answer 34

amphetamine

Question 35

The dominant role of the amygdala is _____
also involved in _____

Answer 35

classical conditioning
memory MODULATION

Question 36

Is the amygdala necessary for activation of memories

Answer 36

No, it is involved and can modulate, but there are other parallel pathways that can modulate instead