Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

L2 Neural Circuits > Modern Questions in Learning and Memory > Flashcards

Modern Questions in Learning and Memory Flashcards

1
Q

How does classical conditioning work? (3)

A
  • Unconditioned stimulus causes an unconditioned response
  • Present a conditioned stimulus before the unconditioned stimulus to associate the two
  • The conditioned stimulus on its own then causes the response to the unconditioned stimulus = the conditioned response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is classical conditioning done in flies? (3)

A
  • Present odour A and B to the flies
  • Associate odour A with an electric shock
  • Give the flies a choice between the two odours, the flies avoid odour A and choose odour B
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which cells are in the Mushroom body?

A

Kenyon cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do drosophila respond sparsely to odours? (3)

A
  • Each Kenyon cell requires multiple simultaneous inputs from projection neurons to reach threshold
  • This converts a dense combinatorial code in the projection neurons into a sparse selective code in the Kenyon cells
  • Each Kenyon cell responds to a specific combination of odours = selectivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is reward/punishment associated with odour in drosophila? (2)

A
  • Dopaminergic neurons respond to reward/punishment and modify the output of the Kenyon cells
  • This leads to a behaviour associated with the odour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does the GAL4/UAS system work? (3)

A
  • GAL4 is a transcription factor from yeast
  • Insert GAL4 into the genome under the control of a promoter which drives expression of GAL4 in specific cells
  • GAL4 binds to UAS and causes transcription of whatever is downstream of UAS e.g. GFP etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the UAS?

A

Upstream activating sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the split-GAL4 system? (3)

A
  • Split the GAL4 gene into the DNA binding domain and the activation domain, put each one under a different promotor
  • Very specific subsection of cells in which both promoters will be active so both halves of the GAL4 protein are made, zip together and cause expression of the UAS-transgene
  • Allows for greater specificity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which part of the brain in drosophila is responsible for olfactory memory?

A

Mushroom body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the structure of the mushroom body? (3)

A
  • Kenyon cells have their dendrites in the calyx
  • Kenyon cells send axons down the peduncle
  • The axons split to form the vertical lobe and horizontal lobe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are MBONs? (3)

A
  • Mushroom body output neurons
  • Receive input from the Kenyon cells
  • Encode value (good/bad experience) and lead to approach/avoidance behaviour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are DANs?

A

Dopaminergic neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does olfactory learning occur in the mushroom body? (3)

A
  • Reward DAN axons innervate the same section of the mushroom body as the avoidance MBON dendrites
  • Punishment DAN axons innervate the same section of the mushroom body as the approach MBON dendrites
  • Learning occurs by the DANs weakening the synapse between the Kenyon cell and the avoid or approach MBON
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does the order of reward/punishment and odour change the behavioural response of the flies? (4)

A
  • Flies learn to approach an odour if it is presented after a punishment
  • Flies learn to avoid an odour if it is presented before a punishment
  • Flies learn to approach an odour if it is presented before a reward
  • Flies learn to avoid an odour if it is presented after a reward
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What mechanism allows for plasticity in olfactory learning in drosophila?

A

DAN activity coinciding with Kenyon cell activity onto an MBON

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 types of dopamine receptor on Kenyon cells in drosophila?

A

DopR1 and DopR2

17
Q

What kind of receptors are DopR1 and DopR2?

A

G protein coupled receptors

18
Q

Which G protein is DopR1 coupled to:

A

Gs

19
Q

Which G protein is DopR2 coupled to:

A

Gq

20
Q

What happens when DopR1 is activated? (2)

A
  • Adenylyl cyclase is activated which produces cAMP
  • Leads to acquisition of memory
21
Q

What happens when DopR2 is activated? (3)

A
  • PLC is activated which makes IP3 and DAG
  • IP3 causes release of Ca2+ from the endoplasmic reticulum
  • Leads to forgetting
22
Q

What is the equivalent of adenylyl cyclase in drosophila?

A

Rutabaga

23
Q

How do the different dopamine receptors respond to different orders of odour and reward? (3)

A
  • When reward happens before odour, DopR1 and DopR2 pathways are both active but DopR2 outweighs DopR1, causing synaptic potentiation i.e. backward learning
  • When reward happens after odour, DopR2 is inactive so the DopR1 pathway causes synaptic depression i.e. forward learning
  • Learning occurs by DANs weakening the synapse
24
Q

What is EPAC?

A

Sensor for cAMP

25
Q

What is forward learning?

A

When conditioning the flies with odour then reward causes them to approach the odour

26
Q

What is backward learning?

A

When conditioning the flies with reward then odour causes them to avoid the odour

27
Q

How does the DopR2 pathway determine the order of odour and reward and respond specifically? (4)

A
  • IP3 receptor is sensitive to IP3 and Ca2+
  • Ca2+ presence signals that the Kenyon cell is active (odour), IP3 presence signals that the DAN is active (reward)
  • If Ca2+ is present before IP3, channel is locked = no ER Ca2+ released
  • If IP3 is present before Ca2+, channel is open = ER Ca2+ released
28
Q

How is optogenetics used to study olfactory learning? (3)

A
  • Implant channelrhodopsin in specific neurons
  • Apply light and see what behaviour results (i.e. approach/avoid etc.)
  • Can be used to activate specific dopaminergic neurons and ‘implant’ memories
29
Q

How are quantitative behavioural experiment used to study olfactory learning? (2)

A
  • Conditioning flies to associate an odour with an electric shock
  • Present a choice of odours to the flies and count how many choose each one
30
Q

What is the equivalent of Kenyon cells in the human cerebellum?

A

Granule cells

31
Q

What is the equivalent of projection neurons in the human cerebellum?

A

Mossy fibres

32
Q

How is the mushroom body structure conserved in humans? (3)

A
  • Granule cells converge onto Purkinje cells
  • The output of granule cells is modified by climbing fibres
  • Climbing fibres encode an error signal to correct ‘wrong’ movements
33
Q

How is the cerebellum/mushroom body structure conserved in the electric fish?

A

Electric organ sends a copy of its own signal that it produced to the Purkinje-like cells so if a signal is received from the granule cells at the same time as the efferent-copy the signal is identified as ‘self’ and ignored

L2 Neural Circuits (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions