Memory and Amnesia

Question 1

What are the two main types of long term memory

Answer 1

• declarative

- non declarative

Question 2

What are the two types of declarative memory

Answer 2

• episodic - personal episode’s in time and space
• semantic - facts, meanings, concept and knowledge
• these require conscious recall

Question 3

What is a type of non-declarative memory

Answer 3

procedural - skills and habits

- this does not require conscious recall as you automatically know how do to it

Question 4

What areas of the brain is associated with episodic and semantic memory

Answer 4

Episodic

• hippocampus,
• medial temporal lobe
• neocortex

Semantic

• lateral and anterior temporal cortex
• prefrontal cortex

Question 5

What area of the brain is associated with procedural memory

Answer 5

• Striatum
• cerebellum
• motor cortex

Question 6

What is the major cellular mechanism for learning and memory

Answer 6

• Long term potentiation

Question 7

Describe the theory behind how Long term potentiation works

Answer 7

 LTP is the persistent strengthening of synapses, which causes a long-lasting increase in signal transmission between 2 neurones.
 The repeated stimulation of a synapse causes more dendritic receptors to appear,
which increases the amount of NT and leads a stronger link.

Question 8

What happens in long term depression

Answer 8

• This is the opposite to long term potentiation
• this is when the memory is no longer needed and not recalled therefore the synapses involved in the memory will reduce in weakness

Question 9

What receptors is LTP and LTD heavily involved with

Answer 9

• LTP/LTD is heavily involved in NMDA and AMPA receptors that bind glutamate.

Question 10

What is

• anterograde amnesia
• retorgrade amnesia
• dissociative amnesia

Answer 10

Anterograde Amnesia:
 New events are not transformed to long-term memory.
Retrograde Amnesia:
 Unable to recall events which have happened before the onset of amnesia.
Dissociative Amnesia:
 Blocking out of critical, personal information.

Question 11

What are the processes required for information to be learned

Answer 11

• Input: acquisition (perception and encoding)
• Hold: storage (consolidation and maintenance)
• Output: retrieval (performance, recall, recognition).

Question 12

Why might you forget information

Answer 12

Forgetting: may be due to temporal decay/interference from other learning.
• Most input is immediately forgotten

Question 13

What memory is distorted in scizhiophrenia

Answer 13

Semantic memory, this usually depends on the prefrontal cortex which can be distorted in schizophrenia

Question 14

What area of the brain is important for priming and perceptual learning

Answer 14

neocortex

Question 15

What are of the brain is used in simple classical conditioning

Answer 15

Amygdala and cerebellum

Question 16

Name 3 types of amnesia

Answer 16

• anterograde
• retrograde
• dissociative

Question 17

What is involved in spatial memory

Answer 17

the hippocampus

- this allows you to be aware of your surroundings

Question 18

What happens to receptors in LTD

Answer 18

 If weakened pre-synaptic signal = only AMPA activated.

 NMDA channel remains closed because it spore is blocked by Mg+ ions.

Question 19

what happens to receptors in LTP

Answer 19

 Large amount of glutamate release and binds to AMPA post-synaptically.
• AMPA stay open longer = greater depolarization.
 This expels magnesium from the NMDA channel.
• This also allows calcium into the cell which allows LTP induction.
o Gene transcription to create new proteins for memory formation.

Question 20

What are the causes of amnesia

Answer 20

• physical trauma
• infection
• drug and alcohol abuse
• reduced blood flow to the brain
• infections such as encephalitis and herpes

Question 21

What does the ability to make LTP depend on

Answer 21

• Synapse number
• Release probability – increase the release probability by increasing the action potentials generating EPSP
• AMPARs their number, phosphorylation state or indeed a combination of the above

Question 22

How can LTP and LTD both be dependent on NMDARs and Calcium

Answer 22

• LTP and LTD are complementary types of plasticity
• The size and time course of NMDA receptor activation and calcium influx differ between LTP and LTD induction
• Induction of LTP produces a large intracellular calcium rise for a short period of time
• Induction of LTD produces a smaller rise in calcium over a longer time scale
• This leads to differential activation of enzymes with different sensitivities to calcium
• Kinases involved in LTP are relatively insensitive to calcium and therefore need a big calcium change to be activated
• Phospatases involved in LTD are relatively more sensitive to calcium and therefore are activated by small calcium changes