Cerebellum

Question 1

When you see a climbing fiber in the cerebellar cortex; where does the cell body ‘live’?

Answer 1

[contralateral inferior olive]

Question 2

What is the name of the sole output neuron of cerebellar cortex?

Answer 2

[Purkinje]

Question 3

The cerebellum communicates with the rest of the brain through which fiber tracts?

Answer 3

[cerebellar peduncles]

Question 4

Who are the deep nuclei of the cerebellum?

Answer 4

[The major output neurons of the cerebellum. Four clusters of neuron below cerebellar cortex, lateral to medial: dentate, emboliform, globose, fastigial (don’t eat greasy food). The dentate is by far the largest. Globose and emboliform are also known as interpositus nuclei. Deep nuclei receive input from Purkinje cells. Deep nuclei neurons are glutaminergic, except those that target the inferior olive which are GABAergic]

Question 5

Which cerebellar peduncle provides the main input to the cerebellum?

Answer 5

[the middle cerebellar peduncle (brachium pontis), by far. It seems to be pure input, no output]

Question 6

Which cerebellar peduncle is nearly all axons from the deep nuclei?

Answer 6

[superior, brachium conjunctivum]

Question 7

Does the rubrospinal tract depend on cerebral cortex for its ‘drive’?

Answer 7

[No, cerebellum is just fine]

Question 8

Among the deep nuclei, which one is largest?

Answer 8

[in human, the dentate nucleus, by far]

Question 9

Which deep nuclear group of cerebellum is associated with the flocculonocular lobe?

Answer 9

[fastigal]

Question 10

Identify the fiber tracts by which the cerebellum communicates with the rest of the brain?

Answer 10

[ the peduncles, inferior, middle, superior. Aka… restiform body, brachium pontis, brachium conjunctivum]

Question 11

Among the 5 neuron types that are fully in cerebellar cortex, only one is excitatory. Which?

Answer 11

[Granule cells; the other 4 types are GABAergic; mossy fibers and climbing fibers originate outside the cerebellum]

Question 12

The _______ make synaptic contact with ______ cells, and serve as the main input to cerebellar cortex?

Answer 12

[mossy fibers, granule]

Question 13

Granule cell axons have a special name…. what is it?

Answer 13

[parallel fibers]

Question 14

The climbing fibers are among the most powerful synapses in the brain. Whom do they wrap themselves around?

Answer 14

[Purkinje cells]

Question 15

Identify the 3 ‘modules’ of cerebellum?

Answer 15

[vestibulocerebellum (flocculonodular lobe + part of vermis, spinocerebellum (vermis, intermediate), neocerebellum (lateral cerebellum)]

Question 16

What seems to be the function of the vestibulocerebellum- and spinocerebellum?

Answer 16

[comparator: copies of command signals are compared to execution signals. If a mismatch occurs, the error appears as an increase in complex spikes in Purkinje cells…the system then adjusts. Calibration (‘gain control’) for all 5 eye movement systems are embedded in the flocculonodular lobe. Gain control for head and body movements including balance are embedded in the vermis and para-vermis.

Question 17

Spinocerebellar fibers contain what two pieces of information?

Answer 17

[proprioceptive and overall ‘tone’ of spinal motor neuron activity]

Question 18

Identify clinical symptoms associated with midline cerebellar damage?

Answer 18

[ataxia (truncal), vertigo, nausea, titubation, nystagmus, tremor]

Question 19

Identify clinical symptoms associated with lateral cerebellar damage?

Answer 19

[ataxia (limbs) impaired check, hyporeflexia, dysarthria, decomposition of movement, past-pointing, scanning or explosive speech, slurred speech, dysdiadochokinesia, tremor (especially of distal limbs)].

Question 20

What is dysdiadochokinesia?

Answer 20

[besides the longest neurologic term, it refers to an impairment in performing rapid, alternating movements]

Question 21

Which is the largest cerebellar module, which targets the dentate nucleus of deep cells, and which seems involved in motor learning?

Answer 21

[lateral or neocerebellum is correct for all]

Question 22

Damage to the left cerebellum will result in motor deficits on the __________?

Answer 22

[left]

Question 23

Is there any primary sensory afferent that reaches cerebellar cortex?

Answer 23

[Yes. Some vestibular primary afferents (cell bodies in Scarpa’s ganglion) terminate in cerebellar cortex as mossy fibers]

Question 24

Climbing fibers synapse onto?

Answer 24

[Purkinje cells]

Question 25

What is the special name of the mossy fiber synapse with granule cell dendrite?

Answer 25

[glomerulus]

Question 26

Identify the major arteries for blood supply to the cerebellum?

Answer 26

[posterior inferior cerebellar, anterior inferior cerebellar, superior cerebellar]

Question 27

What fissure separates the flocculonodular lobe from the rest of the cerebellum?

Answer 27

[posterolateral]