Basal Ganglia Flashcards
(89 cards)
1
Q
What are the components of the corpus striatum (2)
A
- Caudate
2. Lentiform nucleus
2
Q
What are the components of the lentiform nucleus (2)
A
- Putamen
2. Globus pallidus
3
Q
What make up the basal ganglia (5)
A
- Caudate
- Putamen
- Globus pallidus
- Subthalamic nucleus
- Substantia nigra
4
Q
What are the components of the striatum (neostriatum) (2)
A
- Caudate
2. Putamen
5
Q
True or False:
The basal ganglia participates in complex networks that influence descending motor systems
A
True
6
Q
True or False:
The basal ganglia does not project directly to the periphery
A
True
7
Q
True or False:
Movement abnormalities associated with the basal ganglia disorders differ markedly from those of the cerebellum
A
True
8
Q
What does lesion to the basal ganglia result in (2)
A
- Hyperkinetic
2. Hypokinetic
9
Q
What are hyperkinetic movement disorders
A
Uncontrolled voluntary movements that produce a random pattern of jerks and movements
10
Q
What are hypokinetic movement disorders
A
Characterized by rigidity, slowness, and difficulty initiating movements
11
Q
When does hyperkinetic movement occur
A
You have lost your modulation (inhibition) of the movement
12
Q
When does hypokinetic movement occur
A
You have excessive modulation (inhibition) of movement
13
Q
What are the 4 main channels of the basal ganglia
A
- Motor
- Oculomotor
- Prefrontal
- Limbic
14
Q
True or False:
Each channel of the basal ganglia passes through slightly different pathways and projects to different regions of the frontal cortex
A
True
15
Q
What is the major motor channel function of the basal ganglia
A
Disinhibition
16
Q
True or False:
the motor channel function provides feedback to the cerebral cortex for the initiation and control of procedural movements
A
True
17
Q
What does the motor channel do (2)
A
- Facilitates intentional movements
2. Inhibits extraneous movements
18
Q
The motor channel forms a lop that originates in almost every area of the cerebral cortex and eventually terminates after enormos convergence with the basal ganglia on (2)
A
- The upper motor neurons in the motor and premotor areas of the frontal lobe
- Superior colliculus
19
Q
What 2 cortices do not communicate with the basal ganglia
A
- Primary auditory cortex
2. Primary visual cortex
20
Q
True or False:
The parietal cortex allows us to detect motion in the visual field
A
True
21
Q
In an anterior slice of the basal ganglia can you see the globus pallidus
A
No
22
Q
In a posterior slice of the basal ganglia can you see the globus pallidus
A
Yes
23
Q
Why are the caudate and putamen collectively referred to as striatum
A
Due to the striated look in between them
24
Q
What causes the striated look
A
Axon bridges communicating between the caudate and the putamen
25
How do you know that you are in a posterior slice of the basal ganglia
You can see the globus pallidus
26
Where do virtually all of the basal ganglia afferents arrive
Striatum
27
What does the caudate primarily receive input from (5)
1. Premotor cortex
2. Limbic regions
3. Cortical association regions
4. Frontal eye fields
5. Supplementary motor areas
28
What does the putamen primarily receive input from (4)
1. Primary motor cortex
2. Primary somatosensory cortex
3. Substantia nigra (pars compacta)
4. Centromedian nucleus of thalamus (indirect cortical input)
29
Most of the cortical inputs of the basal ganglia afferents for motor channel are ______ and use _____
1. Excitatory
| 2. Glutamate
30
Dopamin input from the pars compacta causes what at the D1 and D2 receptors
D1 receptors: excitatory
| D2 receptors: inhibitory
31
Do basal ganglia outputs inhibit or excite the thalamus
Inhibit
32
Where do the basal ganglia outputs arise from (2)
1. Substantia nigra pars reticulata
| 2. Internal segment of the globus pallidus
33
What do the outputs from the substantia nigra pars reticulata act on (2)
1. Head
| 2. Neck
34
What do the outputs from the internal segment of the globus pallidus act on (1)
1. Body
35
Are the outputs inhibitory or excitatory
Inhibitory (GABA)
36
Where do the main pathways of the basal ganglia outputs go (4)
1. Ventral lateral nuclei of the thalamus
2. Ventral anterior nuclei of the thalamus
3. Intralaminar nuclei
4. Mediodorsal nucleus
37
What do the main pathway of the basal ganglia outputs that go to the ventral lateral and ventral anterior nuclei of the thalamus travel via
The thalamic fasciculus
38
Is the direct loop a positive or negative feedback loop
Positive feedback loop
39
Does the direct loop travel to the external or internal segment of the globus pallidus or both
Internal globus pallidus
40
Is the indirect loop a positive or negative feedback loop
Negative feedback loop
41
Does the indirect loop travel to the external or internal segment of the globus pallidus or both
Both internal and external
42
Does the direct loop excite the cortex or dampen it
Excites the cortex
43
Does the indirect loop excite the cortex or dampen it
Dampens the cortex
44
Direct loop order (4)
1. The cortex excites the striatum
2. The striatum inhibits the globus pallidus internus or substantia nigra reticulata
3. The thalamus is no longer inhibited
4. The thalamus more excitatory signals to the cortical motor areas
45
Indirect loop order (6)
1. The cortex excites the striatum
2. The striatum inhibits the globus pallidus externus
3. The subthalamic nucleus is no longer inhibited by the globus pallidus externus
4. The subthalamic nucleus excites the globus pallidus internus or substantia nigra reticulata
5. The globus pallidus internus or substantia nigra reticulata inhibit the thalamus
6. The thalamus sends fewer excitatory signals to the cortical motor areas
46
Use the figures that Kashino has in our notes to draw the pathways
The ones Naomi gave us are different (even though they are probably what actually happens)
47
What is motor behavior determined by
The balance between the direct and indirect striatal outputs
48
With hyperkinetic disorders what happens to the direct and indirect pathways
Excessive direct pathway output (makes sense this pathway causes more motion)
Insufficient indirect pathway output
49
With hypokinetic disorders what happens to the direct and indirect pathways
Insufficient direct pathway output
| Excessive indirect pathway output (makes sense this pathway causes less motion)
50
Are all basal ganglia signals ipsilateral or contralateral
Contralateral
51
True or False:
Huntington's disease is an autosomal dominant single gene defect that codes for an abnormal protein kills particular pathways
True
52
What pathway is effected in Huntington's disease
The indirect pathway
53
What in the indirect pathway is damaged with Huntington's disease
Neurons in the striatum particularly those of the caudate nucleus
54
What does losing input from the indirect pathway lead to
Motor cortex gets too much excitation
55
What does the excess cortical excitation lead to
Continuous rhythmical movements of the body (especially in the limbs and face)
56
True or False:
| Hungitngton's in the advanced stages is associated with dementia
True
57
What causes hemiballismus
A unilateral lesion to the subthalamic nucleus
58
What does the unilateral lesion prevent
Excitatory subthalamic nucleus projections to the globus pallidus
59
What does the lack of excitation of the globus pallidus result in
Loss of inhibition of the thalamus which greatly increases excitation of the cortex
60
What is the biggest sign of hemiballismus
Large amplitude involuntary movement of proximal limb muscles of a more rotating or flinging quality
61
True or False:
| The signs of hemiballismus can wax and wane but can worsen over time
True
62
What is tardive dyskinesia
Hyperkinetic disorder characterized by involuntary movements of the tongue and face
63
What tongue and face motions occur
Repetitive chewing movements and the tongue moves in and out of the mouth
64
Are the arms affected with tardive dyskinesia
Nope
65
Does lesion cause tardive dyskinesia
Nope
66
What causes tardive dyskinesia
Long term use of antipsychotic drugs that block dopamine
67
What is thought be the effect of the antipsychotic drugs on dopamine that cause tardive dyskinesia
Imbalance of D1 and D2 receptors favoring the direct pathway over the indirect pathway
68
What are the 3 stages of tourette's syndrome
1. Only multiple tics (twitches of the face, limbs, or the whole body)
2. Inarticulate cries are added to multiple tics
3. Emission of articulate words with echolalia (repeating words said by others) and coprolalia (swearing)
69
What is the onset of tourette's syndrome
2-15 years old
70
What ameliorates (makes better) tourette's syndrome
Drugs that block dopamine
71
What causes parkinson's disease
Reduction of dopamine in the brain and damage to the dopaminergic pathway from the substantia nigra pars compacta to the striatum
72
Normally does dopamine in the striatum appears to have an excitatory or inhibitory effect on the direct pathway
Excitatory effect
73
Normally does dopamine in the striatum appears to have an excitatory or inhibitory effect on the indirect pathway
Inhibitory effect
74
Does dopamine normally have an excitatory or inhibitory effect on the thalamus
Excitatory
75
What are the major symptoms of parkinson's disease (3)
1. Resting tremor
2. Cogwheel rigidity
3. Bradykinesia
76
True or False:
| Parkinson's patients can have Lewy bodies in the substantia nigra
True
77
Is progressive supranuclear palsy a progressive or non-progressive condition (please don't get this one wrong)
Progressive
78
What are the symptoms of progressive supranuclear palsy (PSP)
Motor symptoms similar to Parkinson's disease and difficulty walking and frequent falls early in the course of the disease
79
What is a hallmark of progressive supranuclear palsy and how they correct it
Inability to move the eyes up and down (vertical gaze palsy). Corrected by moving the head up and down
80
True or False:
| People with progressive supranuclear palsy have speech and swallowing problems
True
81
True or False:
| People with progressive supranuclear palsy may also think slowly and have trouble keeping their eyelids open
True
82
True or False:
| There is no known cure or way to stop the progression of progressive supranuclear palsy
True
83
What is the goal of treatment for progressive supranuclear palsy
Minimize the complications associated with disease progression and improve the patient's overall quality of life
84
What is the cause of progressive supranuclear palsy
The cause is unknown but related to degeneration of midbrain (including substantia nigra)
85
True or False:
| People with progressive supranuclear palsy present with hummingbird sign
True
86
What is hummingbird sign
Midbrain atrophy without pontine atrophy forming the silhouette of the hummingbird (or penguin) sign
87
Does progressive supranuclear palsy occur above or below the cranial nerves
Above
88
What are the hyperkinetic conditions (4)
1. Huntington's Chorea
2. Hemiballismus
3. Tardive dyskinesia
4. Tourette's syndrome
89
What are the hypokinetic conditions (2)
1. Parkinson's disease
| 2. Progressive supranuclear palsy (PSP)
