Task 3 Flashcards
(57 cards)
1
Q
What are three layers of the cerebelllum ?
A
- Cerebrocerebellum
- Spinocerebellum
- Vestibulocerebellum
2
Q
Where is the Cerebrocerebellum located ? What is the function of it ? From what does it get the input from ?
A
- Location: lateral cerebellar hemisphere (outer part
- Input: indirectly from cortex
- Function: Regulation and guidance of highly skilled movements
3
Q
Where is the spinocerebellum located ? What is the function of it ? From what does it get the input from ?
A
- Location:median (vermis) + paramedian zone
- Input: directly from spinal cord
- Function:
1. paramedian zone = movement of distal muscles
2. Vermis = movement of proximal muscles
4
Q
Where is the Vestibulocerebellum located ? What is the function of it ? From what does it get the input from ?
A
- location: caudal-inferior lobes (contains flocculus + nodulus) and it is the bottom part
- Input: vestibular nuclei in brainstem
- Function: Regulation of movement underlying posture (halting) & equilibrium(balance)
5
Q
What are the 3 major gates/pathways of the cerebellum or also called penduncles ?
A
- Superior cerebellar peduncles
- middle cerebellar peduncles
- Inferior cerebellar peduncle
6
Q
What is the function of the Superior cerebellar peduncles ?
A
- Efferent pathway
- Deep cerebellar nuclei -> superior colliculus -> dorsal thalamus -> pre-motor primary motor areas
7
Q
What is the function of the middle cerebellar peduncles ?
A
- Afferent
- orginates from contralateral side of pons -> via cortex and collicullus to pontine nuclei of pons where transverse pontine fibes cross -> there it reaches the middle peduncles -> cerebellar cortex
8
Q
What is the function of the inferior cerebellar peduncles ?
A
- Afferent and efferent
- Afferent: gain info from vestibular nuclei, spinal cord, tegmentum (stay ipsilateral)
- Efferent: send info to vestibular nuclei and reticular formation
9
Q
Where do the 3 broad divison of the cerebellum go trough ?
A
- deep cellular nuclei
10
Q
What are the names of the 4 deep cellular nuclei ?
A
- Dentate Nucleus
- Two interposed nuclei
- Fastigal nucleus
11
Q
Which nuclei gets the information from what kind of divison ?
A
- The cerebrocerebellum projects to the dentate nucleus
- The spinocerebellum projects to the interposed and fastigial nuclei
- The Vestibulocerebellum projects to the vestibular complex
12
Q
What kind of nuclei is good for what kind of motor activity ?
A
- Dentate nucleus: motor plaining
- interposed nuclei and fastigal nuclei: for motor execution
- vestibular nuclei: for balance
13
Q
What kind of pathway does the divison cerebocerebellum have ?
A
- Ascending (towards cortex)
- Divided in 3 major loops (feedback closed and open)
- All of them run parallel
14
Q
Where is the feedback loop of the cerebrocerebellum located ? And what is it major function ?
A
- from parvocellular red nucleus to inferior olive
- crucial for adaptive function
15
Q
Where is the closed loop of the cerebrocerebellum located ? And what is it major function ?
A
- send info to non-motor areas of the cortex from which signals originated
- modulates cognitive programs
16
Q
Where is the open loop of the cerebrocerebellum located ? And what is it major function ?
A
- input from multiple cortical areas, output to motor cortices
17
Q
What kind of pathway does the divison spinocerebellar have ? (Ascending) and what is it majr function ?
A
- interposed nuclei project via superior peduncle to thalamus to frontal lobes
- wanted movement
- towards cortex
18
Q
What kind of pathway does the divison spinocerebellar have ? (Descending) and what is it major function ?
A
- Fastigial nuclei (vermis) -> inferior peduncle -> reticular formation &superior collicullus and vestibular complex
- governing and axial and promximal limb muscles
- away from cortex
19
Q
What kind of pathway does the divison Vestibulocerebellar have ? and what is it major function ?
A
- Away from cortex
- Inferior peduncle towards vestibular complex towards lower motor neurons
- Function: governs movement of eyes, head, neck, compensating for linear & rotational movement of the head
20
Q
What are the 3 layers of the purkinje cell ?
A
- Granuella cell layer
- Purkinje cell layer
- Molecular layer
21
Q
What does the Granuella cell layer contain ?
A
- mossy fibers, granule cells, Golgi cell
- lower part
22
Q
What does the Purkinje cell layer contain ?
A
- middle part
- bodies of purkinje cell
23
Q
What does the Molecular cell layer contain ?
A
- upper part
- Climbing and parallel fibers and dendrites of purkinje cell and stellate cell
- also the area for electrical input
24
Q
What is the major function of the purkinje cell ?
A
- ultimate destination of afferent pathways
- Purkinje cell tonically inhibit deep nuclei
25
What is the function of the mossy and climbing fibers ?
- exitation of deep nuclei
| - exiataion of purkinje cell (straighten also the inhibition)
26
What is the indirect input pathway regarding ?
- Mossy fibers which rise from cerebral cortex and spinal cord synapse on
1. deep nuclei
2. Granule cell
Follow 2: Granule cells give rise to parallel fibres that synapse on purkinje cells (t-shape structure)
27
What is the direct input pathway regarding ?
1. From Inferior olive -> climbing fibres -> purkinje cell towards -> deep nuclei
2. Inferior olive -> deep nuclei
28
What is so special regarding the deep cerebellum nuclei ?
- it is constantly changing between INHIBITION AND EXITATION
- because of purkinje cell inhibition and exitation of parallel and mossy fibers
- Neurons fire selectively for contraction vs. relaxation of specific muscles, positions of joints & direction
29
What is the function of the Basket and Stellate cells ?
- provides an inhibitory input to the Purkinje cell dendrites
- less activation of purkinje ceel
30
What is the function of the golgi cell ?
- receive input from parallel fibres and then inhibit those exact cells (feedback loop or control centrum)
31
What is the difference between parallel fibers and climbing fibers ?
- parallel fibers fire all the the time
| - climbing fibers once and very strong (look at the youtube video !!!)
32
What is meant with the Marr-Albus theory of motor learning ?
- the idea that motor learning is served by plasticity of the parallel fiber-Purkinje cell synapse
- caused by parallel activation on purkinje cell by parallel and climbing fibers
33
Is albus motor theory correct ?
- paired stimulation of parallel and climbing fibers
| - affects only on parallel fibres that are active at the same time as the climbing fibres -> LTD
34
What are the results of Mars Albums theory ?
- Internalisation (herreinziehen) of AMPA receptors for glutamate in postsynaptic purkinje cell
- smaller EPSP
- less sensitive -> LTD
35
How does the purkinje cell and deep nuclei work regarding error correction ? (VOR glass experiment)
1. Head and eye movement work in a coordinated way
2. Glases change the coordination (eye move to far)
3. Parallef fibers fire constantly
4. Due to recognition of error climbing fibers fire
5. Parallef firing leads to internalization of receptor
6. Purkinje cell can not fire any more
7. Cerebellum fixed the condition
36
What is so special regarding cerebellum damage ?
- Movement errors following cerebellar damage is always on the same side of the body
- Ipsilateral
37
What is the generall problem when the cerebellum is damaged ?
- lack of coordination of ongoing movement
38
What is so special regarding damge in the cerbellum ?
- cerbellum is topographically organized
| - movemnets deficit can be very specific
39
What happenss regarding alcohol abuse and cerebellum ?
- Degeneration of anterior cerebellar cortex (lower limb movements)
40
What is meant with cerebellar ataxia ?
- jerky & imprecise movements (cause by Cerebellar lesions)
41
What is meant by nystagmus ?
- difficulty of eyes in maintaining fixation drift from target then jump back
42
What is meant by Action/intention tremors ?
- over & undershooting of movements
43
What is meant by Dysdiadochokinesia ?
- difficulty performing rapid alternating movements
44
What where the results of the air puff experiment ?
- When cerebellum Is lesioned: Sound comes rabbit still closes eye but to late
- When cerebellum is functioning: Sound comes and rabbit perfectly closes the eyes
45
What is the major function of the cerebellum ?
- balanced and keeps movements smooth (especially timing wise)
- also for error correction
46
What is the function of the TMS ?
- investigate neural networks by stimulating neural structures in humans noninvasively
- it can also only show damge regarding efferent pathways of the cerebellum
47
What did TMS studio figured our regarding cereballar ataxia ?
- Cerebellar ataxia is caused by lesions in fronto-pontine-cerebello-thalamo-cortical loop
48
What does the forward model explain ?
- So the forward model, if accurate, rapidly predicts whether a motor programme will achieve its goal before it is carried out based on current state body information
49
Why is the negative feedback contorl not sufficient enough regarding movemnet ?
- Negative feedback control is too slow, that is why most of our movements are preprogrammed
- short delay of 50-150ms
- Forward model allready focus right away on info and senory knowledfe which negative feedback does not
50
How do error occur regarding the forward model ?
- actual feedback doesn’t match the prediction
51
How does practice of a skill effect the activity of the cerebellum ?
- Activation of cerebellum decreases with practice showing reduction in error as skills improve
52
Inverse model ????
(ASK ELENA)
53
What is menat by the afferent copy state estimation ?
- knowing where your body is at the moment ?
54
Expplain the afferent copy state estimation based on the TMS example:
- Forward model is fine
- But u still have reaching errors
- because the TMS Is blocking part of the cerebellumnd parietal prefrontal cortex
- So wehn sound occurs and TMS is active particpant would reach into direction of the stmuli but based on last state information
55
Why can't we tickle ourself ?
- When a movement is self-produced, its sensory consequences can be accurately predicted, and this prediction can be used to aweaken the sensory effects of the movement
56
Why do we weaken certain stimuli based on expectation ?
- to focus more on relevant info
57
By what is suprise mediated ?
- somatosensory and anterior cingulate cortex
