LTP and spatial learning: drug and genetic manipulations

Question 1

Who provided an example of the general idea of LTP?

Answer 1

Bliss & Lomo (1973) - WS=WR, SS=SR, WS=SR. Presynapstic neuron = post synaptic neuron

Question 2

Where have many demonstrationso f LTP been found and what is this area said to be important for?

Answer 2

Hippocampus - spatial learning

Question 3

What drug blocks NMDA receptors?

Answer 3

AP5

Question 4

Who did a series of experiments involving AP5 and what did they show?

Answer 4

Morris (1989) - - AP5 drug treated rats = impaired performance on Morris water maze

Question 5

What happened if rats were given AP5 after learning spatial task?

Answer 5

Morris (1990) - if given drug after learning spatial task = peformance was not impaired. However, if they had to learn new locations in pool after taking drug = impaired

Question 6

What conclusion can be drawn from Morris (1990) study?

Answer 6

AP5 impairs initial learning – NMDA receptor = necessary for LTP to take place

Question 7

Who did a contradicotry study to Morris (1990)

Answer 7

Bannerman et al (1995) - if rates learned water maze in one room, were then drugged, and learnt in new room - not impaired

Question 8

What conclusion can be drawn from Bannerman et al’s study?

Answer 8

NMDAreceptors are not necessary for learning new spatial tasks

Question 9

What can explain the difference in results of Morris and BAnnerman’s studies?

Answer 9

New location - same pool = learning to unlearn previous rule

New location - new room - learning new information, nothing blocking this learning

Question 10

what conclusions can be drawn from BAnnerman and Morris studies together?

Answer 10

NMDA receptors are necessary for learning new locatrion in a familiar environment when the new information contradicts previously learnt spatial information

Question 11

what role does NMDA recptor and therefore NMDA receptor realted LTP have on spatial learning

Answer 11

Might not be important/its role may be limited to particular conditions

Question 12

Who came up with another condition under which AP5 effects vary?

Answer 12

Steel & Morris (1999) - rats - submerged platform. Location changed from session to sesion but not within. AP5 impaired performance when gap betwee ntrial 1 and 2 = >20 mins

Question 13

What conclusions can be drawn form STeel & Morris experiment?

Answer 13

AP5 impairs retention of new learning, but spares ST retention

Question 14

Why might drug manipulation not be a good test of LTP? examples…?

Answer 14

MAy have side effects e.g. effect NMDAR outside hipipocampus, motivational changes (less anxious) etc

Question 15

How do you make a KO mouse?

Answer 15

Embroynic stem cells from mouse - introduce DNA contianing mutant gene. Inject altered cells into embryo - implant into surrogate mother - give birth. Mate babies - some offspring will have both copies of mutant gene = KO mouse

Question 16

Experiment involving KO mice and Morris WM?

Answer 16

Tsein et al (1996) - mice lackiing NR1 sub-unit of NMDA receptor = impaired on MWM. Lack of NR1 = no functioning NMDA receptor

Question 17

Why would you want to over express parts of MDA receptors?

Answer 17

To eradicate issues of non-specific effects –> to find out does enhancing LTP also enhance performance?

Question 18

What are Doogie mice?

Answer 18

Overexpress NR2B - sub-unit of NMDA receptor.

Question 19

Who did an experiment with Doogie mice?

Answer 19

Tang et al (1999) – Doogie mice showed enhanced learning inn Morris WM and enhance object recognition. More NR2B = more LTP

Question 20

Conclusion from TAng et al experiment?

Answer 20

eEvidence that LTP is imporatnt for learning

Question 21

Who fruthered evidence of importance of NR2B sub-unit?

Answer 21

von Englehardt et al (2002) – NR2B-KO mice = not impaired on acquisition of water maze. Advantage over controls on probe test too - put down to not extinguishing searching behaviour in the target quadrant. Conc - NR2B mice = impaired on everything = no normal performance on any behavioural measure

Question 22

What ahppens with NR2B KO mice on T maze?

Answer 22

They have impaired spontaneous alternation. This involves remembering last move = memory = impaired

Question 23

What are teh two errors on radial arm maze?

Answer 23

Spatial reference memory error and spatial working memory error

Question 24

What is spatial reference meemory error?

Answer 24

Enter arm which is not paried with a reward

Question 25

What is a spatial working memory error?

Answer 25

Enter arm which has been previously entered in the trial. Reflects alternation behaviour. Trial specific

Question 26

What are NR1-KO mice impaired on?

Answer 26

Impaired on SWM. Normal SRM

Question 27

What other mice have same pattern as NR1-KO. What is it?

Answer 27

Imparied on SWN. Normal SRM. NR2B-KO AND GLUA1-KO.

Question 28

Which of SRM oR SWM is involved in associatve learning?

Answer 28

SRM

Question 29

Who did an experiment into the differences between learninig and LTP?

Answer 29

Gallistel & Matzel (2012)

Question 30

In what areas did Gallistel & MAtzel find differences (2012) betwen LTP and learning?

Answer 30

Timing
Persistnece
Reacquisition

Question 31

Timing differences between LTP and learning

Answer 31

LTP = ms, associative earning can be secs, mins, hours

Question 32

What differences did theyf ind in persistence between learning and LTP?

Answer 32

LTP - long lasting, not LT. Associative learning = LT (indefinately_

Question 33

What differences are there in re-acquisition betwen learning and LTP

Answer 33

LTP - just as long/as much effort. ASsociative learning- reacuqition = more rapid than initial acquisition