Lecture 12, Cerebellum

Question 1

Roles of Cerebellum

Answer 1

key role in regulating movement by regulating functions of motor pathways

compares info about the intention of an upcoming movement by receiving info from motor systems to what actually occurs

Question 2

Nonmotor functions of Cerebellum

Answer 2

receives info from higher order sensory areas, contributes to language/decision making/affect

Question 3

Superior cerebellar peduncle

Answer 3

mainly carries outputs from the cerebellum

Question 4

Middle cerebellar peduncle and inferior cerebellar peduncle

Answer 4

mainly carry inputs

Question 5

Functional divisons of cerebellum

Answer 5

Vermis
Intermediate part
Lateral part

Question 6

Vermis

Answer 6

proximal and trunk muscle control, balance, VOR
influences medial longitudinal fasciculus

Question 7

Intermediate part

Answer 7

control of more distal appendicular muscles in arms and legs
influences LCT and rubrospinal

Question 8

Lateral part

Answer 8

planning the motor program for the extremities
influences lateral corticospinal tract

Question 9

Dentate Nucleus

Answer 9

largest of DCN, receive projections from the lateral cerebellar hemispheres
active just before voluntary movements, playing predictive.anticipatory role

Question 10

Interposed Nuceli

Answer 10

receive input from the intermediate part of the cerebellar hemispheres
active during and in relation to movement

Question 11

Fastigial Nuclei

Answer 11

input from the vermis and a small amount from flocculonodular lobe. most fibers project to vestibular nuclei and function

Question 12

Inputs to the cerebellum

Answer 12

mossy fibers
climbing fibers

Question 13

Mossy fiber inputs

Answer 13

ascend through cerebellar white matter to form excitatory synapses on dendrites of granule cells

granule cells–> send axons into molecular layer, form parallel fibers

parallel fibers fun perpendicular to dendritic trees of purkinje cells

P cells form inhibitory synapses onto the DCN and vestibular nuclei

Question 14

Climbing fibers inputs

Answer 14

Carry the ERROR message

Wrap around cell body and proximal tree of purkinje cells

strong modulatory effect on purkinje cells, help to decrease the cell response

Question 15

Output of Cerebellum

Answer 15

axons of purkinje cells into the cerebral white matter

Question 16

INhibitory cells of cerebellar cortex

Answer 16

basket cells and satellite cells
golgi cells

Question 17

Deficits in coordination occur _______ to the lesion

Answer 17

ipsilateral
pathways from the cerebellum are double crossed, first in the superior cerebella peduncle
second in corticospinal and rubrospinal

Question 18

______ lesions in cerebellar vermis effect ______ motor system

Answer 18

Midline
Medial

medial motor systems influence trunk bilaterally

Question 19

Lateral lesions

Answer 19

affect distal limb corrdination

Question 20

Medial Lesions

Answer 20

affect trunk control, posture, balance and gait

Question 21

Lateral cerebellar hemisphere purpose

Answer 21

involved in motor planning
will be carried by purkinje cells to the DCN

projects to dentate nucleus to the superior cerebellar peduncle to reach the VL nucleus of the thalamus to then motor cortex to corticospinal systems

Question 22

Additional output pathway of lateral hemisphere

Answer 22

some fibers terminate in rostral parvocellular division of red nucelus
projects to inferior olive via central tegmental tract

likely involved in timing of movements

Question 23

Intermediate Cerebellar Hemisphere outputs

Answer 23

involved in control of ongoing movements of distal extremities

projects to the interposed nuclei, leaves the cerebellum via the superior cerebellar peduncle to contralateral VL thalamus. influences lateral corticospinal tract

also will project to magnocellular division of red nucelus to influence rubrospinal tract

Question 24

Outputs from Cerebellar Vermis and Flocculonodular Lobe

Answer 24

Begins in vermis, goes to Fastigial Nuceli
carried by superior cerebellar peduncle, crosses and synapse on VL thalamus to influence anterior corticospinal tract and tectal area

also, outputs from fastigial nuclei leave via juztarestiform body to reticular formation and vestibular nuclei (do not cross)

Question 25

Main Cerebellar Output pathways

Answer 25

Lateral hemispheres
Intermediate hemi
Vermis
Inferior vermis and flocculonodular lobe

Question 26

Lateral hemisphere output

Answer 26

path: superior cerebella peduncle
targets: VL of thalamus and red nucleus

Question 27

Intermediate hemispheres output

Answer 27

path: superior cerebella peduncle
target: VL, magnocellular red nucleus

Question 28

Vermis outputs

Answer 28

path 1: Superior cerebellar peduncle
target 1: VL, tectum

path 2: uncinate fasciculus, juxtarestiform body
target 2: reticular formation, vestibular nuclei

Question 29

Inferior vermis and flocculonodular lobe outputs

Answer 29

path: juxtarestiform body
target: medial longitudinal fasciculus (eye movements)