Learning and Memory

Question 1

What is Hebb’s theory on learning and memory?

Answer 1

learning is the response of the brain to environmental evens which involves adaptive changes in the synaptic connectivity; cells that fire together, wire together

Question 2

What is temporal LTP?

Answer 2

summation of inputs reaches a stimulus threshold that leads to the induction of LTP

Question 3

What is associative LTP?

Answer 3

simultaneous stimulation of a strong and weak pathway will induce LTP at both pathways

Question 4

What was the Morris Water Maze Experiment?

Answer 4

rats were required to find a hidden platform in a water bath, spatial learning and memory was measured

Question 5

What was concluded from the Morris Water Maze Experiment?

Answer 5

rats with hippocampal lesions were unable to learn where the platform was

Question 6

What is the role of NMDA receptors in learning?

Answer 6

given an NMDA receptor antagonist prevents LTP and hence learning

Question 7

What is specific LTP?

Answer 7

the LTP at one synapse is not propagated to adjacent synapses

Question 8

What is LTP?

Answer 8

the mechanism underlying synaptic strengthening

Question 9

How are EPSP’s increased?

Answer 9

phosphorylation of existing AMPA receptors increasing their effectiveness and stimulation of insertion of more AMPA receptors into membrane

Question 10

What is early phase LTP?

Answer 10

lasts a minute to an hour, explained by the action of Ca2+ through NDMA receptor and consequent AMPA efficiency

Question 11

What is late phase LTP?

Answer 11

lasts for hours, days or months, explained by protein synthesis creating new synapses and other morphological changes involving CREB

Question 12

What is Long Term Depression?

Answer 12

low frequency stimulation causing a decrease in EPSP as AMPA receptors are dephosphorylated and removed from the membrane

Question 13

What is the function of Theta rhythms?

Answer 13

to synchronise activity in different brain regions

Question 14

What tasks involved Theta rhythms?

Answer 14

running, swimming, head movements and spatially oriented tasks

Question 15

Where are Theta rhythms observed?

Answer 15

in the hippocampus

Question 16

How do genetics affect learning?

Answer 16

increased amounts in a particular type of NDMA receptor leads to enhanced LTP

Question 17

How does age affect learning?

Answer 17

the number of NDMA receptors decreases with age

Question 18

How does environment affect learning?

Answer 18

mice in impoverished environments show greater deficits than those in normal or enriched environments

Question 19

How does associative LTP work?

Answer 19

repeatedly stimulating a strong and a weak pathway simultaneously strengthens the weak synapse

Question 20

Where does associative LTP frequently take place?

Answer 20

in the amygdala during fear conditioning

Question 21

How is fear conditioning achieved?

Answer 21

strong input from the US depolarises the postsynaptic cell, the weak input from the CS is strengthened by this depolarisation leading to activation of the NMDA receptors causing LTP