L10 motor disorder

Question 1

What is the striatum made of?

Answer 1

Caudate nucleus and putamen

Question 2

Where does the cerebellum get input from?

Answer 2

Motor and sensory cortex (via pons), spinal cord and vestibular system (sense of balance)

Question 3

How does the cerebellum send output back to motor cortex?

Answer 3

Via deep cerebellar nuclei and thalamus

Question 4

Name a deep cerebellar nuclei.

Answer 4

Dentate nucleus

Question 5

What are peduncles?

Answer 5

Major fibre tracts

Question 6

Motor cortex neurons project to ____, and then to cerebellum then project directly to ____

Answer 6

pontine nuclei; spinal cord

Question 7

Input from the pons forms ____, onto _____ in cerebellar cortex

Answer 7

mossy fibre input; granule cells

Question 8

Granule cells form parallel fibres which synapses onto ______

Answer 8

Purkinje cells

Question 9

How does Purkinje cells learn associations between parallel fibre inputs?

Answer 9

Climbing fibre inputs from the inferior olive as teaching input

Question 10

What does the basal ganglia compose of? (5pts)

Answer 10

Putamen and caudate
globus pallidus (external &internal)
substantia nigra (pars compacta& .. reticulata)
ventral tegmental area
subthalamic nucleus

Question 11

Name the motor loop process.

Answer 11

Cortex -> putamen -> GPi (directly, indirectly) -> GPe -> optionally STN
GPi -> thalamus -> cortex

Question 12

Basal ganglia loops projections all occur in a _____

Answer 12

somatotopic (homunculus) framework

Question 13

Even numbers of inhibition is what kind of pathway?

Answer 13

Direct pathway

Question 14

Odd numbers of inhibition is what kind of pathway?

Answer 14

Indirect pathway

Question 15

What does indirect pathway do to the cortex?

Answer 15

More inhibition, less activity in cortex

Question 16

What pathways are inhibitory?

Answer 16

From putamen, from GPi, from GPe

Question 17

Dopaminergic inputs from substantia nigra pars compacta play what kind of role in basal ganglia?

Answer 17

Regulating and shaping the pathways

Question 18

What does tonic dopamine release from substantia nigra pars compacta do to D1 and D2 dopamine receptors?

Answer 18

D1: makes their neurons more active
D2: less active

Question 19

What is the relationship between dopamine release, direct pathway activity and motor output?

Answer 19

Positively related

Question 20

What is the cause of Parkinson’s disease?

Answer 20

Degeneration of dopaminergic neurons in the substantia nigra pars compacta

Question 21

What are the prominent symptoms of Parkinson’s disease?

Answer 21

Slowness of movement (bradykinesia), difficulty in initiating movements and tremor

Question 22

What is L-DOPA the precursor of…?

Answer 22

Melanin and dopamine

Question 23

Why substantia nigra neurons black?

Answer 23

Common biochemical pathway for melanin and dopamine

Question 24

How can L-DOPA treat Parkinson’s?

Answer 24

Make the remaining SNc cells produce more dopamine

Question 25

Under what condition will L-DOPA works well to treat Parkinson’s?

Answer 25

When the degeneration is partial

Question 26

What is the common side-effect of L-DOPA therapy?

Answer 26

Dyskinesia

Question 27

Cause of dyskinesia.

Answer 27

Too much dopamine produced

Question 28

What will too much dopamine produced cause on thoughts?

Answer 28

Bad spontaneous ‘motor ideas’ are executed unfiltered

Question 29

What is stem cell therapy for Parkinson’s disease?

Answer 29

Make new dopaminergic neurons from stem cells to inject into basal ganglia

Question 30

Undifferentiated stem cells are rare in ___ but common in ____

Answer 30

adults; embryos

Question 31

What is MPPP?

Answer 31

A synthetic heroin substitute

Question 32

What is MPTP?

Answer 32

A contaminant that can arise from MPPP synthesis

Question 33

What does MPTP do?

Answer 33

Kills dopaminergic neurons and makes people (and animals) instantly have severe Parkinson’s

Question 34

How to treat MPTP poisoned addicts?

Answer 34

Embryonic tissue grafts

Question 35

Where does deep brain stimulus target?

Answer 35

Subthalamic nucleus

Question 36

What causes Huntington’s disease?

Answer 36

Genetic mutation of the HTT gene on chromosome 4, causes premature neural cell death in homozygous carriers

Question 37

Which part is firstly affected for Huntington’s disease?

Answer 37

Spiny stellate neurons projecting from putamen to the GPe

Question 38

Where does the Huntington’s disease damage? and what will this cause?

Answer 38

The indirect pathway; not enough inhibitory control on spontaneous movement

Question 39

Which loop is under dopaminergic control?

Answer 39

Limbic parts of the brain, forms loops through the basal ganglia (cognitive and limbic loops)

• motor loop
• executive loop
• limbic loop

Question 40

Describe motor loop.

Answer 40

Motor cortex -> putamen -> lateral globus pallidus, internal segment -> ventral lateral nucleus -> motor cortex

Question 41

Describe executive loop.

Answer 41

Dorsolateral prefrontal cortex -> dorsolateral caudate -> medial globus pallidus, internal segment -> medial dorsal and ventral anterior nuclei -> cortex

Question 42

Describe limbic loop.

Answer 42

Anterior cingulate cortex -> ventral striatum -> ventral pallidum -> medial dorsal nucleus -> cortex

Question 43

What is used to treat psychiatric diseases, e.g., OCD, tourette’s , anxiety, psychotic states?

Answer 43

Dopamine antagonists

Question 44

Name the dopamine antagonists.

Answer 44

Dopamine, chlorpromazine

Question 45

What is the common side effects of dopamine antagonists?

Answer 45

Parkinson’s disease