L7 - Cerebellum and Motor Learning Flashcards Preview

Neural Basis of Movement > L7 - Cerebellum and Motor Learning > Flashcards

Flashcards in L7 - Cerebellum and Motor Learning Deck (26)
Loading flashcards...
1
Q

What percentage of neurons in the brain are found in the cerebellum?

A

Over 50%

2
Q

What inputs information into the cerebellum?

A

Mossy fibres and climbing fibres

3
Q

Where do the inputs into the cerebellum feed into?

A

Purkinje cells

4
Q

How many mossy fibres are needed to activate one purkinje fibre?

A

200

5
Q

How many climbing fibres are needed to activate one purk`inje fibre?

A

1

6
Q

The output from the cerebello cortex projects to what?

A

Deep cerebellar nuclei.

7
Q

If someone had a lesion to their cerebellum, what would they suffer from?

A

Inability to make accurate movements.

8
Q

What is ataxia?

A

A loss of co-ordination and skill

9
Q

What is hypermetria?

A

An overshoot of fine/precision movement. Gross movement is fine, but the accuracy of the finer movement lacks - means putting finger to nose is more difficult.

10
Q

What is intention tremor?

A

A tremor that is induced from movements, or when focussing on a certain task.

11
Q

What might happen should cerebellum damage occur?

A
  • Ataxia
  • Hypermetria
  • Intention tremor
  • Nystagmus, balance, speech deficits
  • Cerebellar affective disorder: executive, emotional and personality issues.
12
Q

Where does the cerebellar nuclei project/output to?

A
  • Motor and pre-motor cortex

- Spinal cord

13
Q

What is the gain?

A

How much input leads to how much output - calibration process between sensory and motor systems.

14
Q

What happens when there is an error, for example, retinal slip, in the VOR?

A

An error signal transmits through climbing fibres to the Purkinje cells, leading to depression of the synaptic connections. This means that the cell fires less the next time it happens, meaning a stronger response next time (as the Purkinje cells have an inhibitory effect)

15
Q

How do climbing fibres initiate LTD?

A

They fire a teaching signal which causes calcium ions to enter.

16
Q

Explain the role of calcium ions in LTD.

A

Calcium ions internalise AMPA receptors and puts them into stores/recycles them.

17
Q

Why is LTD an associative mechanism?

A

Parallel fibres have to be active/firing at the same time, or during a specific time frame, that the climbing fibres’ teaching signals are active.

18
Q

Spikelets give us an indication of what occurring?

A

Error in our system, in terms of an event occurring that we did not expect.

19
Q

What do climbing fibres cause

A

Simple Spikes and complex spikes.

20
Q

What do simple spikes represent?

A

Signals being sent to Purkinje cells from mossy fibres - indicating that no error has occurred.

21
Q

What do complex spikes represent?

A

Signals being sent to Purkinje cells from climbing fibres- indicating error in the system.

22
Q

Would adults or children be faster at visuomotor adaptation (prism glasses) and why?

A

Adults, as their cerebellum is more developed.

23
Q

What is the main role of the cerebellum?

A

Sensory motor integration and prediction.

24
Q

Where do the climbing fibres and their teaching signals originate from?

A

Inferior olive

25
Q

What is the large output from the cerebellum to the prefrontal lobe for?

A
  • Potential roles in cognitive tasks such as planning, attention and language.
  • Links to autism, affective disorders and dyslexia.
26
Q

What is the Marr-Albus model of learning?

A

Concerns changing the strength of connections between parallel fibres and purkinje cells through long term depression.