Cerebellum

Question 1

What type of memory is the cerebellum involved in forming?

Answer 1

procedural memory

Question 2

If you lesion the cerebellum, what do you NOT have?

Answer 2

paralysis

Question 3

What 3 nuclei of the cerebellum do you need to be able to see on slides?

Answer 3

emboliform nucleus

globose nucleus

dentate nucleus

Question 4

Where is the molecular layer of the cerbellum and what types of cells lie there?

Answer 4

closest to pial surface

basket and stellate cells are there

Question 5

What is the deepest gray matter layer of the cerebellum and what types of cells lie there?

Answer 5

granular layer

contains granule cells and a few golgi cells

Question 6

What is the only excitatory neuron in the gray matter of the cerebellum?

Wat NT does it use?

Answer 6

granule cells

use glutamate

Question 7

What are the output cells of the cerebellum gray matter?

Answer 7

purkinje cells

inhibit the cerebellar nuclei and vestibular nuclei

NT is GABA

purkinje –> deep nuclei –> contralateral cortex via superior peduncle

Question 8

Where are stellate cells found and what do they do?

Answer 8

in the molecular layer

only synapse w/ purkinje cells –> inhibit them

Question 9

Where are golgi cells found and what do they do?

Answer 9

in granular layer of cerebellar cortex

inhibitory neuron using GABA

Question 10

Where are basket cells and what do they do?

Answer 10

found in molecular layer of cerebellar cortex

synapse w/ purkinje cells and inhibit them using GABA

Question 11

What are the types of neurons in gray matter of the cerebellum?

Answer 11

both afferent and excitatory:

climbing fibers from inferior olive –> excitatory to purkinje

mossy fibers from SC, reticular formation, vestibular system and pontine –> granulocytes

Question 12

What type of info do climbing and mossy fibers convey?

Answer 12

climbing: info regarding movement errors to cerebellum
mossy: somatosensory, arousal, equilibrium and cerebral cortex motor info to cerebellum

Question 13

Besides sending info to the cerebellar cortex, where do mossy and climbing fibers send collaterals?

Answer 13

to deep cerebellar nuclei

Question 14

What is the vestibulocerebellum?

Answer 14

fxnal name for the flocculonodular lobe

receives info directly from vestibular receptors –> output to vestibular nuclei

also receives input from visual areas

influences eye movements and postural ms of head and body

Question 15

What is the spinocerebellum and what does it do?

Answer 15

fxnal name for the vermis (midline) and paravermal (just lateral) region

somatosensory info, internal feedback from spinal interneurons, and sensorimotor cortex

controls ongoing movement via the brainstem descending tracts

Question 16

What to medial upper motor neurons of the spinocerebellum do?

Lateral upper UMNs?

Answer 16

medial –> go to posture muscles

lateral –> to limbs, gate, and station

Question 17

What is the pontocerebellum?

Answer 17

also called the neocerebellum or cerebrocerebellum

lateral hemispheres of the cerebellum

input from cerebral cortex via pontine nuclei

coordinates voluntary mvt, planning of movements, and timing

Question 18

Where does the pontocerebellum send fibers to?

Answer 18

purkinje to dentate nucleus –> then to red nucleus and VL nucleus of thalamus

Question 19

What is the posterior spinocerebellar tract?

Answer 19

carries unconscious proprioception from lower limb

1st order neurons enter via DRG and ascend in gracile fasciculus –> synapse in nucleus dorsalis of clark (gray matter from C8-L2) –> 2ndary neuron ascends in dorsolateral funiculus (posterior spinocerebellar tract) –> enters cerebellum via inferior cerebellar peduncle

*stays ipsilateral*

Question 20

What is the cuneocerebellar tract?

Answer 20

axons carry unconscious proprioception from upper limb

1st order neurons enter DRG –> ascend in cuneate fasciculus –> synapse in accessory cuneate nucleus (lower medulla) –> 2ndary fiber ascends to cerebellum and enters via inferior cerebellar nucleus

*stays ipsilateral*

Question 21

What does the anterior spinocerebellar tract?

Answer 21

carries proprioception info to cerebellum

crosses once at anterior white commissure –> to superior cerebellar peduncle –> crosses again to cerebellum

ends up crossing 2x - info ends up on ipsilateral side of cerebellum

Question 22

From where does info entering the cerebellum via the inferior peduncle arise?

Answer 22

inferior olive

spinal cord

vestibular nuclei

Question 23

From where does info come that enters the cerebellum via the middle cerebellar peduncle?

Answer 23

pontine nuclei

Question 24

What efferent routes go through the superior cerebellar peduncle?

Answer 24

from globose, emboliform and dentate nuclei

Question 25

What cerebellar nuclei go to the red nucleus and thalamus?

Answer 25

dentate nucleus globose and emboliform nuclei

Question 26

What is the efferent path from the spinocerebellum?

Answer 26

purkinje fibers to globose and emboliform nuclei --\> through paravermal area --\> to red nucleus and VL nucleus of thalamus

Question 27

What does the fastigial nucleus receive fibers from and where does it send efferents to?

Answer 27

receives from: spinocerebellum and vestibulocerebellum to: reticular formation and vestibular nucleus

Question 28

What is the efferent path from the vestibulocerebellum?

Answer 28

purkinjes to fastigial nucleus or directly to vestibular nucleus via juxtarestiform body fastigial nucleus -vermis-\> reticular formation or vestibular nucleus

Question 29

Where do fibers from the reticulospinal tract come from?

Answer 29

medullary reticular formation pontine reticular formation

Question 30

Where do fibers from the red nucleus go?

Answer 30

to inferior olivary nucleus --\> cerebellar cortex or to rubrospinal tract --\> muscles

Question 31

What do unilateral cerebellar lesions cause?

Answer 31

affect the ipsilateral side ataxia is common to all cerebellar lesions = voluntary, normal strength, jerky, and inaccurate movements **not assoc w/ hyperstiffness** wide gait, **fall toward side of lesion**

Question 32

What do you see in lesions of the vestibulocerebellum?

Answer 32

nystagmus truncal ataxia = difficulty maintaining sitting and standing balance truncal instability (titubation) = ant-post tremor can't tandem walk

Question 33

What do you see in lesions of spinocerebellum?

Answer 33

gait and truncal ataxia

Question 34

What is midline ataxia?

Answer 34

caused by vestibulocerebellar and spinocerebellar disease truncal instability: titubation, gait ataxia equilibratory ataxias (gait)

Question 35

what do you see in lesions of cerebrocerebellum?

Answer 35

dysarthria: slurred, poorly articulated speech ataxic gait decomposition of movements dysdiadochokinesia: inability to rapidly alt movements dysmetria: inability to accurately move an intended distance action tremor

Question 36

What is appendicular ataxia?

Answer 36

dysfunction of cerebellar hemispheres ataxia of the extremities and speech see hypotonia and decomposition of mvt

Question 37

What are the differences btw cerebellar ataxia and sensory ataxia?

Answer 37

cerebellar: romberg test +, unable to stand w/ feet together (w/ or w/out eyes open), normal vibratory sense, propriosense, and ankle reflexes sensory: can stand w/ feet together w/ eyes open, but not closed (+ romberg test), abnormal vibratory, prprioception, and ankle reflexes