Basal Ganglia Flashcards

1
Q

Basal Ganglia- movement

A

Regulate intensity of slow or stereotypes movements
Inhibit antagonistic + unnecessary movements
Switch motor programmes (stop or start)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Neural structures in basal ganglia

A

Caudate nucleus
Putamen
Globus pallidus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Caudate nucleus

A

C shaped nuclei in frontal lobe

Head region curves + extends to form elongated body, tapering at tail and ending in temporal lobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Putamen

A

Large, rounded nuclei located in forebrain

Connected to caudate nucleus at head region of caudate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Globus pallidus

A
Pale body
Internal segment (GPi) --> output to thalamus
External segment (GPe) --> relays info between other basal ganglia nuclei + internal globus pallidus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Internal capsule

A

White matter structure

Separates lentiform nucleus + caudate nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Caudate nucleus blood supply

A

Middle cerebral artery (body)

Anterior cerebral artery (anterior)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Putamen blood supply

A

Middle cerebral artery

Anterior cerebral artery (anterior)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Globus pallidus

A

Middle cerebral artery

Anterior choroidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Internal capsule

A

MCA (middle)
ACA (anterior limb)
Anterior choroidal (posterior limb)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Neuronal projections into basal ganglia are from

A

Cerebral cortex

Substantia nigra pars compacta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cerebral cortex projections

A

Almost all project directly to caudate + putamen
Majority from frontal + parietal
–> projections referred to as corticostriatal pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Substantia nigra pars compacta projections

A

Located in midbrain
Dopaminergic input to caudate nucleus + putamen
–> progressions referred to as nigrostriatal pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Input zone of basal ganglia

A

Corpus striatum- caudate nucleus + putamen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Corpus striatum neurones

A

75% medium spiny neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Inputs to medium spiny neurones

A
Cortical neurones (glutamatergic)
Substantia nigra pars compacta neurones (dopaminergic)
Local circuit neurones within corpus striatum (GABAergic)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Axons arising from medium spiny neurones converge on

A

Neurones in globus pallidus + substantia nigra pars reticulata

18
Q

Medium spiny neurones input

A

Cortical + Substantia nigra pars compacta + Corpus striatum –> medium spiny neurones –> globus pallidus + substantia nigra pars reticulata

19
Q

Output zone of basal ganglia

A

Globus pallidus

Substantia nigra pars reticulata

20
Q

Output zone projections

A

Subthalamic nucleus
VA/VL thalamic nuclear complex
Superior colliculus –> eye movements

21
Q

Subthalamic nucleus

A

Small paired nuclei below thalamus
Input from cerebral cortex + GPe
Projects to GPi and substantia nigra pars compacta

22
Q

VA/VL thalamus complex

A

Input from GPi

Projects to motor areas of cerebral cortex

23
Q

Direct pathway

A

Means for Basal ganglia to facilitate initiation of volitional movement

24
Q

Direct pathway MOA

A

Excitatory glutamate axons project from sensory + association cortices to caudate + putamen
–> project to GPi (inhibitory)
GPi projects to motor thalamus (inhibitory)
–> disinhibition as two negatives in a row
This then projects to motor thalamus + back to supplementary motor cortex

25
Q

indirect pathway

A

Antagonise activity of direct pathway

Stops movement

26
Q

Indirect pathway MOA

A

Output from caudate + putamen goes to GPe and subthalamic
This then goes to GPi
Subthalamic excitatory input to GPi tonic inhibitory action increases inhibition to motor thalamus
–> motor cortex output from motor thalamus remains fixed

27
Q

Rest or doing repetitive movement

A

Direct pathway inactive

Indirect pathway active

28
Q

Change in movement

A

Direct pathway active

Indirect pathway inactive

29
Q

D1 receptor

A

Increases cAMP
Increases sensitivity in corpus striatum neurones to glutamate
Projects to GPi directly via direct pathway
Activated by dopamine

30
Q

D2 receptor

A

Decreases cAMP

Depressed by dopamine

31
Q

Direct pathway receptor

A

D1

32
Q

Indirect pathway receptor

A

D2

33
Q

Parkinson’s

A

Hypokinetic

Over 80% of dopaminergic neurones have to degenerate before clinical signs of disease manifest themselves

34
Q

Early PD

A

Levodopa
Dopamine agonist
MAO-B inhibitors

35
Q

PD with motor + non-motor complications

A

COMT inhibitors
Apomorphine
Amantidine

36
Q

Advanced PD

A

DBS

37
Q

Huntingtons

A

Hyperkinetic
Autosomal dominant
Involuntary movements
Loss of GABAergic neurones in corpus striatum

38
Q

Chorea

A

Rapid, involuntary, jerky-type movements

39
Q

Athetosis

A

Slow, involuntary, smooth, writhing type movements

40
Q

Ballismus

A

Rapid, involuntary, wild flinging-type movements

41
Q

Huntingtons management

A

Amantidine- dystonia, apathy
Benzodiazepine- anxiety
Haloperidol- psychosis
Olanzapine- weight loss