L16: Higher Cortisol Function- Memory Flashcards
What is the definition of learning
Process of acquisition of knowledge or skill
What is the definition of memory
The retention of that knowledge i.e what you have acquired
Is learning and memory the same as stereotypical reflex
No because a stereotypical reflex does not have learning
What are the 2 ways in which we can classify memory
- nature of memory
- duration
What are the 2 types of memory based on the nature of the memory
Declarative
Non declarative
What is declarative memory
Information that is explicit
Consciously aware
Does declarative memory fade or not
Yes it fades with the so you either ‘use it or lose it’
What are the types of declarative memory
Semantic
Episodic
What are semantic memory
Facts
What are episodic memory
remembering a particular Event e.g remembering the meal you had on your birthday but not yesterday
What is non declarative memory
Skills, habits, behaviour
Does non declarative memory fade with time or not
No it is less likely to fade
What are the types of non declarative memory
Procedural
Conditioned response
Emotional response
What is procedural memory
Skills and habits i.e motor tasks e.g riding a bike
What is a conditioned response
Associative reflexes e.g the pavlovas dogs
How do we classify memory in terms of duration
1) input
2) sensory memory
3) short term memory
4) long term memory
What is sensory memory like
Lasts a few seconds
Sensory information e.g vision
What is short term memory
Lasts about 30 seconds
Limited capacity 7+/- items
Lost
What is long term memory
Retained longer than 30 second
How do we go form short term memory to long term memory
Via consolidation related to sleep
If sleep is disrupted what can happen to consolidation
Become disputed
What is working memory
Processing memory and combining it with info in the long term memory
What are the associated factors of forgetting
Increased age
Amnesia
In increased age what structure is lost
Synapses and NOT neurones
What are the causes of amnesia
Traumatic Infection Resection- surgery Stroke Neurodegeneration
What are the 2 types of Amnesia
Anterograde
Retrograde
What is retrograde amnesia
When the individual cannot remember there past before the trauma
Which type of memory is lost in retrograde amnesia
Declarative
What is anterograde amnesia
When you cannot remember the things after the trauma and form new memories
What does current evidence suggest of which parts of the brain are important for different types of memory
A network of connected multiple regions are involved in memory
Different networks have different roles in different memory
Which structure in the brain is important for declarative memory
Medial temporal lobe
In general then what type of memory does medial temporal lobe affect
Episodic then semantic
How does info flow from sensory information to long term memory
1) sensory info passes into short term memory by going through structures in the medial temporal lobe
2) hippocampus and rhinal cortices are associated
3) info passed to neocortex to become long term memory
How does Info flow from the hippocampus to the neocortex
1) hippocampus
2) hypothalamus
3) thalamus
4) neocortex
What does damage from the hippocompus to neocortex pathway result in
Disruption to newly acquired info
What is karsakoffs syndrome
When the mammillary body in the thalamus is affected.
What memory does karsakoffs syndrome affect
The episodic memory
Which structures in the brain are involved in procedural memory
Cerebellum- for smooth muscle coordination
Supplementary motor area (output of basal ganglia) and basal ganglia
What structure in the brain is emotional memory associated with
Amygdala (in the temporal lobes)
What does bilateral temporal lobectomy results suggest
Patient had severe anterograde amnesia for declarative memory
But child hood memory was intact so temporal lobes are not important for long term storage
Which structure does the working memory involve
Pre frontal cortex
What happens to neurones in memory storage
Their state changes - neuroplasticity
What does neuroplasticity involve
Change in neurotransmission
Change in synaptic structures including the number of synapses
What are the ways in which we can change neurotransmission
- Long term potentiation
- long term depression
What does long term potentiation cause
Increase in synaptic activity
What does long term depression cause
Decrease in synaptic activity
When is long term potentiation involved
For declarative memory i.e turning a short term memory into a long term memory
Describe the process that occurs between a pre-synapse and a post-synapse during normal stimulation without LTP
1) pre-synaptic terminal releases glutamate which binds to NMDA and AMPA receptors on the post synaptic terminal
2) if glutamate binds to NMDA and AMPA receptors it will cause movement of ions and depolarisation
3) glutamate bound to NMDA does not have anything happening due to another molecule bound and blocking the entry of ions
Describe the process that occurs between a pre and post synaptic terminal with intense stimulation
1) glutamate that is released from the pre-synaptic terminal binds to AMPA and NMDA
2) NMDA Receptors are now activated as they become unblocked
What is LTP reliant on to cause NMDA receptor activity
Intense stimulation
What goins on to enable LTP
1) NMDA receptors allow calcium influx
2) AMPA receptors do not
3) this involves the activation of CAMK11 (kinase enzyme)
4) enzyme can de phosphorylate proteins which cause enhanced AMPA function to become more sensitive to glutamate
5) in the longer term with persistence effect we can have gene expression resulting in more AMPA receptors
How can we get a change in synaptic structure
1) The axon of a neurone can sprout
2) growth cone with cause another synapse to the post synaptic neurone
3) this gives a greater influence
As the brain ages what happens to the synapse
Rigid synapses do not decreases
Plastic synapses decrease
What drugs can we use to enhance memory
Nootropics
What drugs can we use to suppress memory
NMDA antagonist e.g ketamine
Who would use NMDA antagonist
War field survivors
How can we treat memory non-pharmacologically
Cognitive behaviour therapy- by reactivating synapses
