3.18.14 34 Motor Systems IV (Cerebellum)

Question 1

The neocerebellum is also known as? Consists of what structures?

Answer 1

Lateral cerebellar hemispheres
Middle portion of vermis (midline)

Question 2

The paleocerebellum is also known as? Consists of what structures?

Answer 2

Spinocerebellum
--
Anterior lobes
Some of vermis
Tonsils

Question 3

The archicerebellum is also known as? Consists of what structures?

Answer 3

Flocculonodular lobe

Question 4

What are the three layers of the cerebellar cortex? Name the major cell type(s) of each.

Answer 4

1. Outer molecular layer (inhibitory interneurons: Golgi, Stellate, Basket cells)
2. Purkinje layer (Purkinje cells)
3. Granular layer (Granule cells)

Question 5

What is the general flow of information starting with mossy fibers?

Answer 5

MOSSY fibers –> GLOMERULI (granule cell dendrites in granular layer) –> PARALLEL fibers (granule cell axons in the molecular layer) –> PURKINJE, INHIBITORY INTERNEURONS
–> INTRACEREBELLAR NUCLEI –> output

Question 6

What is the general flow of information starting with climbing fibers?

Answer 6

CLIMBING FIBERS –> PURKINJE CELLS (in outer molecular layer) –> INTRACEREBELLAR NUCLEI –> output

Question 7

Where do climbing fibers originate? What peduncle(s)?

Answer 7

Olivary nucleus (inferior)

Question 8

Where to mossy fibers originate? What peduncle(s)?

Answer 8

Inferior:

• Vestibulocerebellar
• Reticulocerebellar
• Cuneocerebellar
• Posterior Spinocerebellar

Middle (majority of input):
-Pontocerebellar (input from cortex)

Superior:
-Anterior Spinocerebellar

Question 9

Name the intracerebellar nuclei

Answer 9

Dentate
Interposed (Emboliform, Globose)
Fastigial

Question 10

Where in the cerebellum does input to the dentate nucleus originate?

Answer 10

Lateral hemispheres

Question 11

Where in the cerebellum does input to the interposed nucleus originate?

Answer 11

Paravermal regions

Question 12

Where in the cerebellum does input to the fastigial nucleus originate?

Answer 12

Vermis

Question 13

Where do outputs exit the cerebellum? Where are they destined (for each nucleus)?

Answer 13

Superior peduncle
Dentate:
-Red nucleus
-Thalamus
Interposed:
-Red nucleus
Fastigial:
-Reticular formation
-Vestibular nucleus

Question 14

What is a major route of feedback for output of the cerebellum to the cerebellum?

Answer 14

Dentate/interposed –> Red nucleus –> Inferior Olivary Nucleus –> Climbing fibers

Question 15

Climbing fibers synapse with (granule cells/Purkinje cells)

Answer 15

Purkinje cells

Question 16

Mossy fibers synapse with (granule cells/Purkinje cells)

Answer 16

Granule cells

Question 17

What “spatial” organizational benefit comes of the connections of mossy fibers?

Answer 17

Lateral inhibition:
Mossy –> granule –> inhibitory interneurons (Golgi, Basket, Stellate) –> inhibition of adjacent groups of Purkinje cells

Question 18

Intention tremors result from damage to what two structures?

Answer 18

Neocerebellum/pontocerebellum (lateral hemispheres) and the Dentate nucleus

Question 19

Damage to the cerebellum results in contralateral or ipsilateral symptoms?

Answer 19

Output crosses midline and terminates on centers of output that cross back to the same side

Question 20

Axial disturbances (ataxia, imbalance) result from damage to what portion of the cerebellum?

Answer 20

Vermis

Question 21

Distal disturbances (asynergia, decomposition of movement) result from damage to what portion of the cerebellum?

Answer 21

Hemispheres (recall intention tremors)