Learning And Memory Flashcards
What are the two types of memory?
Declarative = something you can learn like facts
non declarative = when you learn a skill like playing a musical instrument
Memory can be?
Short or long term
What helps synaptic vesicle movement?
A large number of proteins like SNARES
What are synaptotagmin proteins? and which ion channel do they move towards?
These are proteins which help synaptic vesicle movement and helps the release of neurotransmitters inside of the vesicles
What do these do?
Detect calcium ion channels
They move the vesicles closer to the calcium channels channels
What is the main role of calcium on vesicles?
They help them to release neurotransmitters
What are the three different pools of vesicles?
Note there are different types of synaptic vesicles but they usually contain the same neurotransmitters
There is the readily realisable pool
- as calcium concentration goes up neurotransmitters are very easily released
The proximal pool
- there is a slightly bigger number of these pools. For the neurotransmitters to be released this needs to switch to the readily realisable pool
The reserve pool
- this needs to be turned into the proximal pool and then the readily realisable pool
What are the three different types of glutamate receptors?
The NMDA receptor
The non - NMDA receptor (AMPA)
The metabotropic glutamate receptor
What is important to note about the NMDA receptor in comparison to the metabotropic and AMPA receptors?
These are more permeable to calcium - let more calcium into the cell
It also responds to other things as well as glutamte
Advantages of studying invertebrates brains?
They have big neurones - the size of this however depends on how big the organism is
They also have much less complex nervous systems - which are easier to study
They are also quite stereotypic - they have neurones which are very easily identifiable and easy detect.
You can also increase/ decrease the temperature of the insect very easily
And you can also have mutant invertebrates which only become mutants when you increase temperature.
What are the two simple forms of memory formation processes?
Habitutation - memorys formed that allow us to stop responding to a particular REPEATED stimuli
Sensitisation - this is when repeated stimuli increases a response.
Habitutation examples
Eye blink reflex
Repetitive exposure to non harmful stimuli - like a busy road
Habituation of visual attention
Habituation of emotions - such as overcoming stage fright
Example of habitutation
How to overcome the gill and siphon withdrawal reflex on aplysia
Aplysia - is a slug like organism
So if you water jet the siphon (a very sensitive organ of the aplysia) you get the withdrawal reflex
If you repeated stimulate - this reduces the reflex . This is an example habitutation
This affects the abdominal ganglion synapse
What causes habitutation?
There is a change somewhere between the pre and post synaptic neurones
Detection of the post synpatic response decrease with time
How are neurotransmitters related to habituation?
Its thought that a reduced neurotransmitter release increase habitutation
An example of causing SENSITISATION with aplysia (using their siphon and gills)?
Poking the siphon (the sensitive part) and giving it an electric shock increases sensitisation
This affects the sensory neurone coming from the siphon and the L29 neurone which releases serotonin - these both synapse onto the same motor neurone
Electric shock causes the neurotransmitter levels to be high enough for a motor neurone to cause a muscle contraction.
What is the mechanism of sensitisation (the simple bear model)?
Stimulation from an electric shock for example causes:
Protein kinase A to phosphorylate and INACTIVATE. Potassium channels in the L29 neurones
This causes there to be a longer depolarisation in the L29 neurones to occur
A longer depolarisation means more vesicular release
More vesicles released means more neurotransmitters are released so action potential occur in the post synaptic vesicles. This allows for sensitisation
So overall what causes habituation and sensitisation?
Habituation is caused be the depletion of the synaptic vesicle pool. Repeated stimulation means the synaptic vesicles neurotransmitters are used up and thus a less response happens with multiple stimulations
Sensitisation is causes by serotonin-ergic feedback from other sensory neurones
What is important to note after sensitisation?
Any conditioned stimulus such as poking a siphon without an electric shock causes a more sensitised response even without a stimulus
During associative learning?
In humans and animals
The L29 neurone and the sensory neurone works at the same time - their depolarisation causes an increase in calcium. This allows for more vesicles to release and increased activity of adenyl cylase = thus more cAMP is released
