Motor Systems: Cerebellum Flashcards Preview

Neuro > Motor Systems: Cerebellum > Flashcards

Flashcards in Motor Systems: Cerebellum Deck (19)
Loading flashcards...
1
Q

What are the deep cerebellar nuclei from lateral to medial? What are their functions?

A

(Don’t Eat Green Frogs)
Dentate, Emboliform, Globose, Fastigial
-Excitatory and lead to activation of neurons in motor control centers

2
Q

What are mossy fibers? What is their purpose? Where do they terminate in the cerebellum?

A

Mossy fibers are a heterogeneous group of afferents carrying reference input and efference copy. ALL afferent inputs to the cerebellum, except for inputs from the inferior olives (climbing fibers), are mossy fibers.

*Produce simple spikes in Purkinje cells, high frequency discharge

Terminate in:

  • Deep cerebellar nuclei (directly excite)
  • Cerebellar cortex (excite granule cells that indirectly excite Purkinje cells)
3
Q

Where do mossy fibers primarily form from?

A
  • the periphery via spin and cuneocerebellar tracts
  • Motoneurons, motor interneurons, and central pattern generators via spino and cuneocerebellar tracts
  • Vestibular info, arriving via the vestibular nerve and nuclei
  • Cortex, including motor, premotor, somatosensory, and visual areas, via a synapse in the pontine nuclei
4
Q

What are Purkinje cells?

A

Only output neuron, inhibitory (GABA) to cerebellar nuclei/vestibular nucleus; receives input from parallel fiber and climbing fibers

5
Q

What are granule cells?

A

Origin of parallel fiber system, excitatory (glutamate) to Purkinje cells and inhibitory interneurons.

6
Q

What are the three inhibitory interneurons?

A

Stellate, basket, and Golgi cells. All excited by parallel fibers

7
Q

What are climbing fibers?

A
  • Come solely from contralateral inferior olive.
  • Monosynaptic to Purkinje cells, resulting in powerful excitation known as complex spikes
  • Low frequency discharge
  • May encode teaching signal
8
Q

Where does the vestibulocerebellum (flocculonodular lobe and vermis) project to?

A
  • Vestibular and fastigial nuclei
  • Medial vestibulospinal tract (controls trunk/neck muscles)
  • Lateral vestibulospinal tract (controls limb muscles)
  • Gaze centers (controls eye movements)
9
Q

The following symptoms are due to disorders of what division of the cerebellum?

  • Disturbances of equilibrium (fall toward side of lesion)
  • Nystagmus
  • Loss of smooth pursuit eye movements
A

Vestibulocerebellum. Lesioning fastigial nucleus has similar effects.

10
Q

Dorsal spinocerebellar tract

A

Type of info: Reafference
Body parts: Legs and trunk
Arises from: Clarke’s nucleus
Enters thru: Restiform body/inferior cerebellar peduncle

11
Q

Ventral spinocerebellar tract

A

Type of info: Efference copy
Body parts: Legs and trunk
Arises from: Ventral horn
Enters thru: Superior cerebellar peduncle

12
Q

Cuneocerebellar tract

A

Type of info: Reafference
Body parts: Arms
Arises from: External cuneate nucleus
Enters thru: Restiform body/inferior cerebellar peduncle

13
Q

Rostral spinocerebellar tract

A

Type of info: Efference copy
Body parts: Arms
Arises from: Ventral horn
Enters thru: Restiform body/inferior cerebellar peduncle

14
Q

The following symptoms are due to a disorder of what area of the cerebellum:

  • Disturbances of gait (vermis)
  • Hypotonia
  • Action tremor
  • Limb ataxia/dysmetria
  • Disorders of timing (dysdiadochokinesia)
  • Decomposition of movements
A

Spinocerebellum. Lesioning the emboli form and globose nuclei has similar effects.

15
Q

Where does the spinocerebellum project to?

A
  • Vermis projects to fastigial nucleus (reticulospinal tract and vestibulospinal)
  • Intermediate zone projects to globose and emboliform nuclei which project to red nucleus (controls rubrospinal tract) and ventral lateral thalamus and the motor cortex (controls corticospinal tract)
16
Q

Where does the cerebrocerebellum (cerebellar hemispheres lateral zones) get input from?

A

-Pontine nuclei

17
Q

Where does the cerebrocerebellum project to

A

Via dentate nuclei to VL of thalamus, prefrontal areas, and red nucleus

18
Q

Damage to what area of cerebellum results in the following symptoms:

  • Ataxia of finest movements
  • Cognitive deficits?
A

Cerebrocerebellum (lesioning the dentate nucleus has similar effects).

19
Q

How does the cerebellum predict the consequences of a motor action?

A

By comparing efferent copies (what is supposed to happen) with reafferents (what actually is happening). Learning is used to improve these predictions.