Learning And Memory

Question 1

What are the two types of memory?

Answer 1

Declarative = something you can learn like facts

non declarative = when you learn a skill like playing a musical instrument

Question 2

Memory can be?

Answer 2

Short or long term

Question 3

What helps synaptic vesicle movement?

Answer 3

A large number of proteins like SNARES

Question 4

What are synaptotagmin proteins? and which ion channel do they move towards?

Answer 4

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

Question 5

What is the main role of calcium on vesicles?

Answer 5

They help them to release neurotransmitters

Question 6

What are the three different pools of vesicles?

Note there are different types of synaptic vesicles but they usually contain the same neurotransmitters

Answer 6

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

Question 7

What are the three different types of glutamate receptors?

Answer 7

The NMDA receptor

The non - NMDA receptor (AMPA)

The metabotropic glutamate receptor

Question 8

What is important to note about the NMDA receptor in comparison to the metabotropic and AMPA receptors?

Answer 8

These are more permeable to calcium - let more calcium into the cell

It also responds to other things as well as glutamte

Question 9

Advantages of studying invertebrates brains?

Answer 9

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.

Question 10

What are the two simple forms of memory formation processes?

Answer 10

Habitutation - memorys formed that allow us to stop responding to a particular REPEATED stimuli

Sensitisation - this is when repeated stimuli increases a response.

Question 11

Habitutation examples

Answer 11

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

Question 12

Example of habitutation

How to overcome the gill and siphon withdrawal reflex on aplysia

Aplysia - is a slug like organism

Answer 12

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

Question 13

What causes habitutation?

Answer 13

There is a change somewhere between the pre and post synaptic neurones

Detection of the post synpatic response decrease with time

Question 14

How are neurotransmitters related to habituation?

Answer 14

Its thought that a reduced neurotransmitter release increase habitutation

Question 15

An example of causing SENSITISATION with aplysia (using their siphon and gills)?

Answer 15

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.

Question 16

What is the mechanism of sensitisation (the simple bear model)?

Answer 16

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

Question 17

So overall what causes habituation and sensitisation?

Answer 17

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

Question 18

What is important to note after sensitisation?

Answer 18

Any conditioned stimulus such as poking a siphon without an electric shock causes a more sensitised response even without a stimulus

Question 19

During associative learning?

In humans and animals

Answer 19

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