Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Functional Neuro > Task 3 > Flashcards

Task 3 Flashcards

1
Q

what is the cerebellum ?

A
  • influences movements by modifying activity patterns of the upper motor neuorns
  • detects the difference between an intended movement and the actual movement (= motor errors)
    -> corrects them
  • two main grey matter structures
    -> laminated cerebellar cortex on surface
    -> deep cerebellar nuclei
    = main source of output
  • made up of three layers
    -> inner granule cell layer
    -> middle Purkinje cell layer
    -> outer molecular layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Of what consists the cerebellar cortex?

A

cerebrocerebellum
spinocerebellum
vestibulocerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the cerebrocerebellum?

A
  • lateral cerebellar hemisphere
  • input = directly from cortex
  • occupies most of the lateral hemispheres
    regulation & guidance of highly skilled movements
  • contralateral

planning and execution of complex
movement -> speech

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the spinocerebellum?

A
  • median strip along the midline
  • Input = directly from spinal cord
  • Occupies
    -> Paramedian zone
    = movement of distal muscles
    -> Vermis
    = movement of proximal muscles & certain eye movements
  • ipsilateral
  • fractured maps
    -> each body part is presented multiple times
    -> mapped topographically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the vestibolucerebellum?

A
  • caudal-inferior lobes
    -> flocculus + nodulus
  • Input = vestibular nuclei in brainstem
  • Regulation of movement underlying posture & equilibrium + vestibulo-ocular reflex
  • ipsilateral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the vestibulo-ocular reflex?

A

having stable vision during fast head movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the cerebellar peduncles

A
  • allow the cerebellum to communicate with the rest of the CNS
  • three pathways
    -> superior cerebellar peduncles
    = efferent
    -> middle cerebellar peduncle
    = afferent
    -> inferior cerebellar peduncle
    = afferent & efferent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the superior cerebellar peduncles?

A
  • efferent
  • neurons from deep cerebellar nuclei
  • ipsilateral
  • their axons project to upper motor neurons in the deep layers of the superior colliculus
    -> after in the dorsal thalamus, primary motor & premotor area
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the middle cerebellar peduncles?

A
  • afferent
  • contralateral
  • receives input from variety of sources
  • cell bodies from pontine nuclei
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the inferior cerebellar peduncle?

A
  • smallest but most complex pathway
  • afferent pathway
    -> from vestibular nuclei, spinal cord, brain stem tegmentum
    -> stay ipsilateral
  • efferent
    -> to vestibular nuclei & reticular formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are inputs to the cerebellum?

A
  • cerebellar pathway
    -> cerebrocerebellum
  • sensory pathway
    -> spinocerebellum
    -> vestibulocerebellum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the output of the cerebellum?

A
  • projections to deep nuclei & vestibular complex
    -> projection to upper motor neurons in the brainstem & thalamic nuclei
  • to deep cellular nuclei
    -> dentate nucleus
    -> two interposed nuclei
    -> fastigial nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the ascending output? And what is the descending output ?

A

Ascending
- cerebrocerebellar pathway
- spinocerebellar pathway

Descending
- spinocerebellar pathways
- vestibulocerebellar pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the cerebrocerebellarpathway?

A

= FEEDBACK loop to the cerebellum

  • from dentate nucleus
  • pre motor cortex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the outline of the cerebellum?

A
  • Mossy fibres
    -> synapse on neurons in the deep cerebellar nuclei + on granule cells
  • parallel fibres
    -> ascend to the molecular layer of the cerebellar cortex
    -> relay excitatory input to dendric spines of Purkinje cells
  • Purkinje cells
    -> receives input from a lot of parallel fibres + direct input from climbing fibres
    -> cell body = Purkinje cell layer
    -> dendrites = projecting to the molecular layer (= deep cerebellar nuclei)
    -> only output of the cerebellar cortex
    -> inhibitory
    -climbing fibres
    -> arises from the inferior olive
    -> modulate parallel fibre connection with Purkinje cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the deep excitatory loop?

A
  • mossy fibres & climbing fibres collaterals excite neurons in the deep cerebellar nuclei
  • input signals converge on the output stage of cerebellar processing
17
Q

what is the cortical inhibitory loop?

A
  • consists of desceding inhibitory input from the Purkinje cells
    -> also driven by mossy & climbing fibres
  • Purkinje cells integrate inputs and invert them, by responding to excitatory input with inhibitory input
  • golgi, stellate, and basket cells control the flow of information through the cerebellar cortex
    -> golgi cells control how much input granule cells provide to purkinje cells
    -> basket cells provide lateral inhibition to purkinje cells
18
Q

How is ongoing movement coordinated?

A
  • purkinje cell & deep cerebellar nuclei are tonically active
    -> change their firing frequency as movement occurs
    -> recognise potential motor errrors by comparing patterns of convergent activity
  • deep cerebellar nuclei sends corrective signals to the motor cortex
    -> to maintain/ improve the accuracy of the movement

=> happens during the movement occurred

19
Q

what is the marr-albus theory of motor learning

A
  • climbing fibres are responsible for relying the message of a motor error to the purkinje celll
    -> serve as teching signal
    -> introduces a long-lasting change in strength of parallel fibre inputs
  • this plasticity happens when it is simultaneously active as climbing fibre input to the post-synaptic purkinje cell
  • if efference copy is the same as real time information (from climbing fibres)
    -> less activity in purkinje cell = no need to learn
  • if efference copy is not the same as real time information (from climbing fibres)
    -> purkinje cells modulates its inhibitorys output
    -> leads to modulated output to the deep cerebellar nuclei
20
Q

what is longt-term depression in the cerebellar cortex?

A
  • in order to induce synaptic plasticity
    -> pairing stimulation of climbing fibres with stimulation of parallel fibres
  • activation of parallel fibres alone resulted in maller postsynaptic responses in the purkinje cells
21
Q

What are consences of cerebellar lesions

A

errors in movement
-> always on the same side

cerebellar ataxia
= difficulties in producing smooth, well coordinated movements
= rather they are imprecise

dysmetria
= over - and underreaching impairments in highly skilled sequences of learned movements (= speech)

22
Q

what is state estimation (process)?

A
  • used to accurately plan and control movement
  • combining sensory information about the last known position of body parts with predictions of their response to recent movement commands
  • CNS never exactly knows the state of the motor apperatus
    -> due to delays
23
Q

what is the forward model?

A
  • anticipation of sensory consequences
  • after neural model has been completed, it can rapidly predict whether a motor programme will achieve its goals before it is carried out
    -> can be adjusted if it seems unlikely
  • after movement:
    model can be updated by comparing its predictions with what happened

= you can predict own movements, making it impossible to ticke oneself

24
Q

what is the inverse model?

A
  • inverts the information flow from the forwards model
  • inputs the desired goal of movement and back
  • calculates the motor commands rewuired to achieve gial

=> generates the program of motor commands required for movement

Functional Neuro (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions