Synaptic plasticity and learning Flashcards
There are 2 types of long term memory in mammals. What are they?
- Declarative
2. Non-declarative
Define declarative memory. Give examples.
Explicit memories that can be consciously recalled, such as facts and events (episodic memory).
Which 2 main brain areas are involved in declarative memory?
- Medial temporal lobe
2. Diencephalon
Define non-declarative memory.
Implicit memories that are not consciously recalled by are evident in our actions.
Non-declarative memory is involved in 2 major functions, what are they?
- Priming
2. Procedural memory
Define priming.
You are ‘primed’ by your experiences. The more often you encounter something, the more likely you are to remember it. The neural pathways become more salient.
Explain procedural memory.
A type of memory that allows us to carry out commonly learned tasks without thinking about them. You can easily perform tasks but cannot describe exactly how you do them.
Non-declarative memory is involved in 2 types of learning. What are they?
- Associative
2. Non-associative
Define associative learning. Give an example.
The process by which an association between 2 stimuli, or a stimulus and a behaviour, is learned.
An example is classic, operant conditioning.
Define non-associative learning. Give an example.
Whereby repeated exposure to a stimulus has a lasting effect on the change in response to that stimulus.
An example is habituation or sensitisation, ‘getting used to’ a stimulus.
Define priming. Which area of the brain is involved?
You are ‘primed’ by your experiences. The more often you encounter something, the more likely you are to remember it. The neural pathways become more salient.
The neocortex is involved in priming.
Which brain area are involved in associative learning?
The cerebellum and amygdala.
Which brain area are involved in non-associative learning?
The reflex pathways.
a) What is the theory of memory storage?
b) Who proposed it?
a) Memories are stored in the brain by anatomical changes to the neurons.
b) Santiago Ramon y Cajal
a) What is the cell assembly theory of memory?
b) Who proposed it?
a) The strength of a synaptic connection is increased when the firing of the pre and postsynaptic neurons are closely correlated in time
b) Donald Hebb
a) What is the RNA theory of memory?
b) Who proposed it?
a) If memory involves synaptic growth then new proteins and thus RNA are required. Thus in exercising particular synapses we should be able to detect changes in RNA levels
b) Holger Hyden
Why are invertebrates often used in memory studies? Give 4 reasons.
- They have fewer neurons.
- They do not have skulls so the brain is more accessible
- The axons are larger
- Networks are simpler
How many neurons does C. elegans have?
302.
Invertebrate cells are clustered in ganglia. Individual ganglia can control certain behaviours. True or false?
True.
Describe Seymour Benzer’s memory experiments with drosophila.
- Set up an apparatus with an electric grid covered in cyclohexanol, a pungent chemical. Every time flies flew near the grid they were electrocuted.
- Then transferred the flies to a different chamber with 2 grids: both were non-electrical but one smelled of cyclohexanol and the other didn’t.
- The flies avoided the cyclohexanol grid because they had been conditioned to avoid it, showing learning.
a) What did Seymour Benzer discover in the drosophila brain?
b) What happened when he removed these?
a) Mushroom bodies.
b) The flies did not remember their training
Seymour discovered 4 types of memory in his drosophila. What were they?
- Short-term (STM)
- middle-term (MTM)
- Anaesthesia-resistant 24hr (ARM)
- Long-term (LTM)
In Benzer’s experiments:
a) How long did LTM last? Did it require protein synthesis?
b) How long did ARM last? Did it require protein synthesis?
a) >2 days, LTM requires protein synthesis.
b) ~24 hours, ARM does not require protein synthesis and was resistant to anaesthesia as long as memory consolidation had taken place.
