Memory + amnesia Flashcards
Describe the divisions of the memory system.
Memory system is composed of:
- Short-term memory
- Long-term memory
Long-term memory is composed of:
- declarative (explicit) component
- non-declarative (implicit) component
Declarative can be divided into:
- episodic (events)
- semantic (facts)
Non-declarative can be divided into:
- procedural (skills + habits)
- priming + learning
- classical conditioning
- non-associative learning
What areas of the brain are associated with:
- episodic (events)
- semantic (facts)
- procedural (skills + habits)
- priming + learning
- classical conditioning
- non-associative learning
Episodic:
- hippocampus
- medial temporal lobe
- neocortex
Semantic:
- lateral + anterior temporal cortex
- PFC
Procedural:
- striatum
- cerebellum
- motor cortex
Priming + learning:
- neocortex
Classical conditioning:
- amygdala
- cerebellum
Non-associative learning:
- reflex pathways
What is anterograde amnesia?
new events are not transferred to long-term memory
deficit in learning subsequent to the onset of the disorder
can happen with damage to the hippocampus
What is retrograde amnesia?
unable to recall events before the onset of amnesia
What is dissociative amnesia?
Blocking out of personal information, usually of a traumatic or stressful nature (psychogenic)
What are the other types of amnesia?
transient global
traumatic
Wernicke’s korsakoff’s psychosis
Which antagonist can cause selective impairment of learning and blockade of LTP?
N-Methyl-D-aspartate receptor antagonist
What is long-term potentiation?
Memories are formed when neurones form new connections/strengthen existing synapses
A persistent increase in synaptic strength (i.e. repeating an action) = long-lasting increase in signal transmission between two neurones = LTP
*repeated stimulation of synapses causes more dendritic receptors to appear
What is long-term depression?
If a memory is no longer needed/rarely recalled, the synapses involved will weaken
reduction in efficacy of neuronal synapses lasting hours/longer following a long patterned stimulus
Which receptors are mostly involved in LTP/LTD? Which neurotransmitter do they bind to?
NMDA + AMPA
Bind to glutamate
What is the state of the AMPA + NMDA channels in LTD?
If there is weakened pre-synaptic signal = only AMPA is activated
NMDA channels remain closed due to spore being blocked by Mg2+ ions
What is the state of the AMPA + NMDA channels in LTP?
Large amount of glutamate release and binds to AMPA post-synaptically
- AMPA stays open for longer = greater depolarisation
Depolarisation expels the magnesium ions from the NMDA channel
- this allows calcium into the cell which allows LTP induction
- gene transcription to create new proteins for memory formation
