Basal Ganglia

Question 1

What is the abnormal repeat in Huntington’s disease?

Answer 1

CAG

Question 2

Does stimulation of the caudate produce movement?

Answer 2

no

Question 3

What is the pars compacta?

Answer 3

the back projection from the striatum to the substantia nigra made by neurons that contain and release dopamine to produce their effects

Question 4

frontal association cortex –> caudate –> _____ –> dorso-medial thalamus –> association cortex

Answer 4

globus pallidus

Question 5

frontal association cortex –> _____ –> globus pallidus –> dorso-medial thalamus –> association cortex

Answer 5

caudate

Question 6

How is activation of a motor control signal achieved in the basal ganglia?

Answer 6

by release of iinhibition

Question 7

What is the juncture btw the caudate and putamen called?

Answer 7

the nucleus accumbens

Question 8

frontal association cortex –> caudate –> globus pallidus –> dorso-medial thalamus –> ______

Answer 8

association cortex

Question 9

frontal association cortex –> caudate –> globus pallidus –> ______ –> association cortex

Answer 9

dorso-medial thalamus

Question 10

What does the nucleus accumbens do?

Answer 10

it processes info from the paleo-cortex as part of the limbic system –> subserves emotional and drive-related aspects of behavior

Question 11

What is the difference btw the D1 and D2 receptor?

Answer 11

• D1 = excitatory, direct pathway to the globus pallidus internal
• D2 = inhibitory, indirect pathway via the globus pallidus external

Question 12

What sensory deficit will be seen in a lesion of the basal ganglia?

Answer 12

none

Question 13

sensori-motor complex –> putamen –> globus pallidus –> VA (and some VL) thalamus –> ______

Answer 13

motor cortex (esp the supplementary motor area SMA)

Question 14

_____ –> putamen –> globus pallidus –> VA (and some VL) thalamus –> motor cortex (esp the supplementary motor area SMA)

Answer 14

sensori-motor complex

Question 15

What is the indirect pathway to the basal ganglia?

Answer 15

the D2 receptors –> globus pallidus external –> substantia nigra –> globus pallidus internal

Question 16

Where does the output from the basal ganglia go to?

Answer 16

from the thalamus –> cortex

Question 17

This processes info from the paleo-cortex as part of the limbic system –> subserves emotional and drive-related aspects of behavior.

Answer 17

the nucleus accumbens

Question 18

The _____ receives a projection from the striatum (caudate + putamen) and projects back to the caudate and putamen.

Answer 18

substantia nigra

Question 19

The substantia nigra receives a projection from the _____ and projects back to the caudate and putamen.

Answer 19

striatum (caudate + putamen)

Question 20

What must be in balance in the basal ganglia for normal function?

Answer 20

dopamine and ACh

Question 21

What does striatal damage cause?

Answer 21

athetosis or chorea

Question 22

These are slow, writing, ceaseless movements of the hands, lips, tongue, neck, and feet.

Answer 22

athetosis

Question 23

What is the NT released in the substantia nigra and in the globus pallidus?

Answer 23

GABA

Question 24

What is the direct pathway?

Answer 24

when the thalamic neurons receive less input from the globus pallidus –> increase firing –> excite cortical neurons

Question 25

Where does the input to the basal ganglia come from?

Answer 25

the cerebral cortex

Question 26

This is a portion of the substantia nigra that projects to the thalamus.

Answer 26

the pars reticulata

Question 27

The subthalamic nucleus receives a projection from the ______ and projects back to both the external and internal segment of the globus pallidus.

Answer 27

external segment of the globus pallidus

Question 28

What causes hemiballismus?

Answer 28

a stroke in the small ganglionic branch of the PCA, leading to damage of the subthalamic nucleus on one side

Question 29

Where do D1 receptors project to?

Answer 29

the globus pallidus internal

Question 30

Unilateral defects of the basal ganglia = ____ deficits in function

Answer 30

contralateral

Question 31

The basal ganglia is important for ____ of motor performance.

Answer 31

modulation

Question 32

What are the 4 nuclei of the basal ganglia?

Answer 32

1. the caudate and putamen 2. the globus pallidus 3. the substantia nigra 4. the subthalamic nucleus

Question 33

The direct pathway ______ movement, while the indirect pathway ______ movement.

Answer 33

facilitates; inhibits

Question 34

What are the cardinal features of Tourette's Syndrome?

Answer 34

motor and phonic tics that fluctuate in severity

Question 35

The ______ receives a projection from the external segment of the globus pallidus and projects back to both the external and internal segment of the globus pallidus.

Answer 35

subthalamic nucleus

Question 36

The subthalamic nucleus receives a projection from the external segment of the globus pallidus and projects back to\_\_\_\_\_\_.

Answer 36

both the external and internal segment of the globus pallidus

Question 37

\_\_\_% of dopamine synthesis occurs at the basal ganglia.

Answer 37

80%

Question 38

Describe the flow of information from the cortex through the basal ganglia and back.

Answer 38

cortex --\> caudate --\> putamen --\> globus pallidus --\> thalamus (VA, VL, or DM) --\> cortex

Question 39

Is muscle strength decreased with a basal ganglia lesion?

Answer 39

no

Question 40

Virtually all _____ and _____ disruption of motor control involves breakdown of function of some portion of the basal ganglia.

Answer 40

nontraumatic; metabolic

Question 41

What is athetosis?

Answer 41

slow, writing, ceaseless movements of the hands, lips, tongue, neck, and feet

Question 42

What comprises the basal ganglia?

Answer 42

a mass of bilaterally gray matter cells at the base of the cerebrum next to the thalamus

Question 43

The substantia nigra receives a projection from the striatum (caudate + putamen) and projects back to the \_\_\_\_\_\_.

Answer 43

caudate and putamen

Question 44

Where do D2 receptors project to?

Answer 44

the globus pallidus external

Question 45

On what chromosome is the Huntington protein encoded?

Answer 45

4

Question 46

What kind of tremor is seen in Parkinson's disease?

Answer 46

a resting tremor

Question 47

What is hemiballismus?

Answer 47

flailing movements of the arm and leg on one side

Question 48

What is the nucleus accumbens?

Answer 48

the juncture btw the caudate and putamen

Question 49

What descending pathway comes from the basal ganglia?

Answer 49

none

Question 50

What are the caudate+putamen called, collectively?

Answer 50

the (neo)striatum

Question 51

What is the purpose of the dual feedback loops in the basal ganglia? How is this achieved?

Answer 51

* to balance facilitation and inhibition of the cortex * via dopamine

Question 52

What is the pars reticulata?

Answer 52

a portion of the substantia nigra that projects to the thalamus

Question 53

What projects directly to the basal ganglia?

Answer 53

nothing

Question 54

What does a stroke in the small ganglionic branch of the PCA, leading to damage of the subthalamic nucleus on one side, cause?

Answer 54

hemiballismus

Question 55

\_\_\_\_\_\_ --\> caudate --\> globus pallidus --\> dorso-medial thalamus --\> association cortex

Answer 55

frontal association cortex

Question 56

sensori-motor complex --\> putamen --\> globus pallidus --\> ______ --\> motor cortex (esp the supplementary motor area SMA)

Answer 56

VA (and some VL) thalamus

Question 57

This is the back projection from the striatum to the substantia nigra made by neurons that contain and release dopamine to produce their effects .

Answer 57

the pars compacta