Learning and memory

Question 1

What types of memories are declarative?

Answer 1

Episodic and semantic

Question 2

What was Donald Hebbs major discovery?

Answer 2

“Cells that wire together, fire together”

Question 3

What mechanism underlies synaptic strengthening?

Answer 3

LTP

Question 4

Who first discovered LTP

Answer 4

Bliss and Lomo, 1973

Question 5

What did Bliss and Lomo observe?

Answer 5

After stimulating the neuron with a high frequency, the single stimulations that followed were causing bigger EPSPs than they were before the neuron was depolorised

Question 6

What does tetanic stimulation mean?

Answer 6

Repeated stimulation

Question 7

What animal experiment is used to test spatial memory?

Answer 7

Morris water maze task

Question 8

At resting potential, if glutamate binds to an AMPA or a NMDA receptor what happens?

Answer 8

AMPA = EPSP due to sodium influx
NMDA = nothing due to Mg block

Question 9

Following depolorisation/HFS, what happens to the NMDA receptor?

Answer 9

Mg block is removed and sodium and calcium are fluxed

Question 10

What is AP5?

Answer 10

NMDA antagonist

Question 11

What happens to rats performance on the morris water maze task , following administration of AP5?

Answer 11

They spend the same amount of time in all the quadrants

Question 12

What happens to the cells response in rats who were injected with AP5 following a HFS?

Answer 12

They return to baseline instead of showing the higher EPSPs

Question 13

What protein does calcium activate in the post-synaptic terminal?

Answer 13

CaMKII

Question 14

What effect does CaMKII have on the AMPA receptors?

Answer 14

1. It phosphorylates the existing ones, increasing their effectiveness
2. Stimulates the insertion of new AMPA receptors into the membrane

Question 15

What does it mean to be autocatalytic?

Answer 15

The first protein it phsophorylates is itself

Question 16

Why can CaMKII be thought of as a molecular switch?

Answer 16

Because when calcium enters it, it opens up

Question 17

Calcium activates nitric oxide synthase which converts to what?

Answer 17

Nitric oxide

Question 18

Nitric oxide diffuses across the synapse and activates a second messanger system, guanylyl cyclase, whcih does what?

Answer 18

Produces cGMP

Question 19

What does cGMP do?

Answer 19

Leads to an increased glutamate release from the terminal boutons

Question 20

What tyoe of CREB promotes transcription?

Answer 20

CREB-1

Question 21

The long term effects of LTP require what?

Answer 21

Protein synthesis

Question 22

CREB-1 works more effectively when it has been phosphorylated, it is phosphorylated by kinases such as?

Answer 22

PKA and CaMKII

Question 23

What occurs as a result of the CREB gene activation?

Answer 23

They make, strengthen and increase the synapses of AMPA receptors

Question 24

How does long term depression occur following LFS?

Answer 24

AMPA receptors are dephosphorylated and removed from the membrane and low level rises in calcium activate phosphatase, which removes phosphates

Question 25

Chen (1996) performed LTP and LTD on what area of the brain that was removed during the course of surgery?

Answer 25

The inferotemporal cortex

Question 26

Tang et al, 1999 made transgenic mice expressing the NB2B receptor and they showed what?

Answer 26

LTP in the mice had a higher response and higher EPSP

Question 27

How did this affect memory? | (after the gene had been inserted)

Answer 27

The rate of acquisition was not remakably different, however the T mice spent more time in the target quadrant than the controls

Question 28

What factors can affect LTP?

Answer 28

1. Enriched environment 2. Age

Question 29

Who found the reversal of ageing effects by enrichment?

Answer 29

Winocur, 1998

Question 30

In the conditioned fear response, what acts as the HFS?

Answer 30

The actual fear stimulus

Question 31

Because they are firing at the same time, the depolorisation effects from neuron A spread to neuron B. What does this mean in relation to neuron B and fear conditioning?

Answer 31

Overtime, activation of just neuron B will lead to a large enough EPSP to create the fear response alone, because it has been strengthened by the postsynaptic depolorisation