BMS248 Lecture 9 - Learning and Memory

Question 1

What is the acquisition of information?

Answer 1

Learning

Question 2

What is the storage of learned information?

Answer 2

Memory

Question 3

What is the reacquisition of stored information?

Answer 3

Recall

Question 4

What is known as the physical embodiment of a memory

Answer 4

The engram

Question 5

What is explicit memory?

Answer 5

Memory that can be consciously recalled - declarative memory

Question 6

What is declarative memory?

Answer 6

Facts and events available to the conscious mind - can be encoded in symbols and language

Question 7

What is implicit memory + what are the 3 types?

Answer 7

Memory that cannot be consciously recalled:
1. Procedural memory
2. Classical conditioning
3. Priming

Question 8

What is procedural memory?

Answer 8

Skills and associations largely unavailable to the conscious mind - e.g. juggling

Question 9

What is classical conditioning

Answer 9

Associating a stimuli with positive/negative reward

Question 10

What is priming?

Answer 10

Exposure to one stimulus influences the response to another subsequent stimuli

Question 11

What are the two simple forms of memory?

Answer 11

1. Habituation
2. Sensitisation

Question 12

What is habituation?

Answer 12

Amplitude of responses reduces with repeated stimulus

Question 13

What is sensitisation?

Answer 13

Amplitude of responses increases with repeated stimulus

Question 14

What is the Aplysia gill withdrawal reflex?

Answer 14

Touch/water jet causes gill withdrawal.
Habituation to repeated stimuli - reduces the reflex

Question 15

What kind of circuit is involved in this reflex?

Answer 15

Typical reflex circuit - glutamatergic

Question 16

Where in the reflex circuit does the habituation occur?

Answer 16

Between the presynaptic sensory neuron and the postsynaptic motor neuron

Question 17

What is the molecular basis of habituation?

Answer 17

Reduced glutamate release leads to the depletion of the readily releasable pool (RRP) in subsequent firing of the neuron - reduced synaptic strength as there is less available synaptic vesicles

Question 18

What leads to sensitisation (increased) of the gill withdrawal reflex?

Answer 18

Tail/head pinch or shock

Question 19

Where does the sensory neuron (L29) that detects this stimulus bind?

Answer 19

To the other sensory neuron, at the pre-synaptic input of the motor neuron

Question 20

What activates a G-protein at this synapse?

Answer 20

Serotonin (5-HT): serotonin-ergic feedback

Question 21

The G-protein leads to activation of pkA (via adenylyl cyclase + cAMP) - what effect does this have? - What is the molecular basis of sensitisation?

Answer 21

pkA phosphorylates and inactivates K+ channels - therefore longer depolarisation means more vesicular release - therefore amplitude of response increases with repeated stimuli

Question 22

What occurs when the weak siphon touch (CS) is paired with the strong shock (US)? - Pavlovian like Associative learning

Answer 22

Ca2+ influx from the conditioned stimulus (siphon touch), synergises the 5-HT effect from the unconditioned stimulus (shock) - MORE cAMP - greater siphon withdrawal

Question 23

Long term sensitisation and conditioning involve what?

Answer 23

The nucleus - changes in gene and protein expression

Question 24

In early stages of sensitising and conditioning what kinases are involved?

Answer 24

1. PKA
2. CamK II
3. PKC