Modulation of movement by basal ganglia and cerebellum

Question 1

what does cerebellum (Cb) and basal gangli (B.G.) do?

Answer 1

modulate activity of UMN

Question 2

the effects of the Cb and B.G are similar or opposite?

Answer 2

opposite

Question 2

what sends information to the BG and Cb?

Answer 2

motor cortex

Question 2

how does Cb and BG send information back to the motor cortex?

Answer 2

through the thalamus

Question 3

what does the contribution of both systems allow for?

Answer 3

smooth, coordinated movement

Question 3

what does a disturbance in BG or Cb result in?

Answer 3

motor disorders

Question 3

what does the BG or nasal nuclei recieve input from?

Answer 3

corticles

Question 4

what are the 5 parts of the BG?

Answer 4

caudate nucleus & putamen (aka striatum)
Globus pallidus
Substantia nigra
Subthalamic nucleus
thalamus

Question 5

which is the direct and indirect pathway of the BG

Answer 5

Question 6

what is disinhibition?

Answer 6

inhibition of inhibition
two inhibitory neurons in a series

Question 7

what does a reduction of inhibition in the GB lead to?

Answer 7

increase in feedback from the thalamus to the cortex

Question 8

which BG pathway increases and decreases thalamic excitation of the cortex?

Answer 8

direct - increases
indirect - decreases

Question 9

is the thalamic output always inhibitory or excitatory

Answer 9

excitatory

Question 10

Pathway of neurotransmitter of basal ganglia

Answer 10

1. cortex -> stiatum : glutamate
2. striatum -> globus pallidus : GABA
3. globus pallidus -> thalamus : GABA
4. subthalamic nucleus -> globus pallidus : glutamate
5. thalamus -> cortex : glutamate

Question 11

which is excitatory and which is inhibitory - glutamate and GABA?

Answer 11

excitatory - glutamate
inhibitory - GABA

Question 12

what has the highest levels of ACh in the brain?

Answer 12

striatum

Question 13

where is dopamine produced and released?

Answer 13

produced - substantia nigra
released - striatum

Question 14

when is dopamine excitatory and when is it inhibitory?

Answer 14

excitatory - direct pathway, D1 receptors
inhibitory - indirect pathway, D2 receptors

Question 15

what is the overall effect of dopamine on thalamic input to the cortex?

Answer 15

increased input

Question 16

when is acetylcholine excitatory and when is it inhibitory?

Answer 16

excitatory - indirect pathway
inhibitory - direct pathway

Question 17

what is the overall effect of acetylcholine on thalamic input to the cortex?

Answer 17

decreased thalamic input to cortex

Question 18

what does hypoactivation of the basal nuceli circuit cause?

Answer 18

hyperkineasia - inc in movement

Question 19

what does hyperactivation of basal nuceli circuit cause?

Answer 19

hypokinesia - dec in movement

Question 20

How is knapweed poisonious to horses?

Answer 20

DDMP inhibits dopamine transport in equine brain

Question 21

which cranial nerves are most affected by yellow star thistle?

Answer 21

V, VII, IX

Question 22

what does russian knapweed intoxication do to the facial muscles?

Answer 22

hypertonicity

Question 23

what does the cerebellum do?

Answer 23

compares intended movement to actual movement and makes adjustement

Question 24

what do cerebellar lesions result in?

Answer 24

ataxia - uncoordinated muscle movement, don't prevent movement or impair strength

Question 25

what are the 3 distinct regions of the cerebellum?

Answer 25

-vestibulocerebellum -spinocerebellum -cerebrocerebellum

Question 26

what allows unconscious control of fine motor movements?

Answer 26

cerebellum

Question 27

what is the main output of the cerebellum?

Answer 27

motor cortex

Question 28

what part of the cerebellum regulates balance and eye movements?

Answer 28

vestibulocerebellum

Question 29

what part of the cerebellum enhances muscle tones and coordinates skilled voluntary movement of different muscle group, and predicts position of body in space during movement?

Answer 29

spinocerebellum

Question 30

what part of the cerebellum plans and initiates voluntary activity, and stores procedural memory?

Answer 30

cerebrocerebellum

Question 31

match each cerebellum region with its inputs inputs - cortex, vestibular system, muscle spindles regions - vestibulocerebellum, spinocerebellum, cerebrocerebellum

Answer 31

cortex - cerebrocerebellum vestibular system - vestibulocerebellum muscle spindles - spinocerebellum

Question 32

what are the layers of the cerebellum?

Answer 32

molecular layer purkinje cell layer granule cell layer white matter

Question 33

what is the only output of the cerebellum?

Answer 33

purkinje cells

Question 34

what are the inputs to the Cb?

Answer 34

-copy of motor plan from cerebral cortex -sensory information from vestibular system, eyes, skin, joints, muscles

Question 35

what integrations does the Cb do?

Answer 35

motor and sensory inputs integrated to make an error correction and adjust posture

Question 36

what is the input of the vestibulocerebellum?

Answer 36

vestibulosensory input from vestibular organ, superior colliculus, striate (visual) cortex

Question 37

where does the output of the vestibulocerebellum go?

Answer 37

vestibulocerebellum -> lateral & medial vestibular nuclei -> vestibulospinal & bulbar tracts

Question 38

what are the functions of the vestibulocerebellum?

Answer 38

coordinate movement of head and eyes control antigravity muscles

Question 39

what happens if the vestibulocerebellum is damaged?

Answer 39

ataxia, poor balance, wide gate

Question 40

what is the input of the spinocerebellum?

Answer 40

spinal and trigeminal sensory inputs auditory inputs, striate (visual) cortex

Question 41

where does the output of the spinocerebellum go?

Answer 41

spinocerebellum -> interposed and fastigal nuclei -> descending brainstem and corticospinal pathways

Question 42

what is the function of the spinocerebellum?

Answer 42

proper execution of coordinated movement

Question 43

what happens if the spinocerebellum is damaged?

Answer 43

dysmetria, functional tremor, decreased muscle tone

Question 44

what is the input of the cerebrocerebellum?

Answer 44

premotor, supplementary and primary motor cortex

Question 45

where does the output from the cerebrocerebellum go?

Answer 45

cerebrocerebellum -> denate nucleus -> red nucleus -> ipsilateral olivary nucleus -> motor and premotor corticles

Question 46

what is the function of the cerebrocerebellum?

Answer 46

planning, initiation, timing learning of motor skills properly timed movement sequences

Question 47

what symptoms are seen in patients with cerebellar lesions?

Answer 47

wide gate, ataxia, dysmetria, asynergia, intention tremor, nystagmus, head bobbing

Question 48

what does canine multiple system degeneration do to the neurological processes?

Answer 48

damages Cb and BG ataxia -> akinesia and severe posture instability

Question 48

why would a Cb lesion prior to the decussation cause an ipsilateral motor deficit?

Answer 48

Cb crosses over twice so the area that it would be affecting is the same side as where the lesion is lesion = no fine tuning of movements = motor deficit

Question 48

where does the superior cerebellar peduncle cross?

Answer 48

caudal midbrain level

Question 49

what is canine multiple system degeneration?

Answer 49

fatal familial movement disorder in dogs

Question 50

what does BVD do to the cows brain?

Answer 50

cerebellar hypoplasia degenerative purkinje cells and loss of granule cell layer -> reduced cerebellum

Question 51

what happens to the cerebellum in kittens with panleukopenia virus?

Answer 51

virus attacks rapidly dividing cells in outer layers of cerebellum -> intentional tremor, ataxia, wide gate, head bobbing