8. Learning and Memory

Question 1

Learning

Answer 1

Acquiry of new info

our experiences change our NS and behaviour

Question 2

memory

Answer 2

after learning —> changes in NS

Question 3

Learning and memory: processes

eating cum saves rice

Answer 3

Encoding (processing of sensory info)
Consolidation (process of integration into LTM)
Storage (long-term record)
Retrieval (accessing stored memories –> new MEMORY TRACE)

Question 4

where is DECLARATIVE memory formed?

Answer 4

hippocampus

Question 5

Dentate Gyrus is found where?

Answer 5

Hippocampus

Question 6

Dentate Gyrus: function?

Answer 6

source of neurogenesis, granulate cells

Question 7

name the 2 main structures within the hippocampus

Answer 7

dentate gyrus

ammon’s horn

Question 8

name the functions of ammon’s horn

and drawbacks

Answer 8

CA1 & CA3 pyramidal cells,
very susceptible to injury,
critical for memory formation

Question 9

What was removed in most lobotomies?

Answer 9

hippocampi
post part of amygdalae
entorhinal cortex

Question 10

Lobotomy: symptoms and consequences?

Answer 10

• anterograde amnesia (heavy)

- retrograde amnesia (temporary)

Question 11

What was NOT affected by a lobotomy?

Answer 11

• intellect
• working memory, lexical memory
• procedural memory

Question 12

LEARNING: new info is stored when…

Answer 12

activity in a circuit causes long-lasting change in the pattern of SYNAPTIC WEIGHTS

Question 13

when are associative memories formed?

Answer 13

• Correlation of presynaptic and postsynaptic firing  synaptic modification  connections strengthened

Question 14

name the most prototypic forms of synaptic plasticity

Answer 14

LTP
LTD
in CA1 area of hippocampus
(NMDA-activation)

Question 15

what is LTP?

Answer 15

repetitive activation of excitatory synapses  potentiation of synaptic strength (hours, days)

Question 16

what is LTD?

Answer 16

reduction in efficiency of synapse

due to repetitive low frequency activation

Question 17

describe the biochemical process of LTP…

Answer 17

1. Activated presynaptic neuron releases GLUTAMATE
2. GLUTAMATE binds with AMPA and NMDA receptors
3. AMPA receptor channel opens and NA+ passes, depolarising presynaptic neuron  EPSP
4. EPSP (polarization) drives Mg2+ OUT  NMDA channel opens
5. CA2+ entry through NMDA channel  activates secondary messenger pathway
6. Secondary messenger pathway…
   - promotes AMPA insertion in postsynaptic neuron  glutamate sensitivity increases
   - Triggers nitric oxide release  permanent increase in glutamate release by presynaptic neuron

Question 18

late-phase LTP

Answer 18

synaptic growth

requirement of gene transcription & new protein synthesis