Week 9: Corpus Striatum

Question 1

List the major structures of the corpus striatum.

Answer 1

• Caudate nucleus
• Putamen
• Nucleus accumbens
• Globus pallidus (pallidum)

Question 2

List the four parallel circuits of the corpus striatum.

Answer 2

• Motor
• Ocular motor
• Prefrontal
• Limbic

Question 3

What is the major output of the striatum?

Answer 3

Inhibitory output to pallidum.

Question 4

Where does the pallidum receive excitatory input from?

Answer 4

The subthalamic nucleus

Question 5

What are the major structures of the basal ganglia?

Answer 5

• Corpus Striatum
• Subthalamic Nucleus
• Substantia Nigra

Question 6

List the components of the striatum.

Answer 6

Caudate Nucleus
Nucleus Accumbens
Putamen

Question 7

What functions are the corpus striatum theorized to be involved in?

Answer 7

initiation of movement
sequencing of movements
Scaling of Movement
Focused Selection

Question 8

Which of the following is NOT correct regarding striatal afferents?

a. Corticostriate fibers are all excitatory
b. Nigrostriate fibers are all excitatory
c. Thalamostriate fibers are all excitatory
d. Somatosensory and motor input from the cortex goes to the putamen
e. Limbic afferents enter innervate the nucleus accumbens

Answer 8

b. Nigrostriate fibers are all excitatory

Some nigrostriate fibers are, excitatory some are inhibitory

Question 9

The Corpus Striatum, Subthalamic Nucleus and Substantia Nigra form the:

a. Telencephalon
b. Basal ganglia
c. Pallidum

Answer 9

b. Basal ganglia

Question 10

Which of the following form the striatum? Select all that apply.

a. Caudate Nucleus
b. Subthalamic Nucleus
c. Substantia Nigra
d. Nucleus Accumbens
e. Putamen
f. Internal Globus pallidus
g. External Globus pallidus

Answer 10

a. Caudate Nucleus
d. Nucleus Accumbens
e. Putamen

Question 11

Which of the following is NOT true regarding striatopallidal fibres?

a. They are all inhibitory
b. They innervate the internal and external globus pallidus
c. They are GABA-ergic
d. They are striatal afferents

Answer 11

d. They are striatal afferents

Question 12

What is the direct pathway?

Answer 12

Cerebral cortex -> Excites Striatum -> Disinhibits thalamus by inhibiting the interal pallidum

Facilitates movement/motor activity

Question 13

What is the lentiform nucleus?

Answer 13

Wedge shape.

Includes the globus pallidus, putament, external capsule, claustrum, extreme capsule, insula

Question 14

Which of the following is NOT true regarding the role of dopamine in the basal ganglia?

a. In the direct pathway dopamine has an excitatory effect on the neostriatum
b. Dopamine helps activate the direct pathway to facilitate movement.
c. In the indirect pathway dopamine binds to D2 receptors that cause inhibition of the neostriatum.
d. In the indirect pathway, dopamine helps to prevent movement.

Answer 14

d. In the indirect pathway, dopamine helps to prevent movement.

TRUTH: By inhibiting the in the indirect pathway, dopamine facilitates movement.

Question 15

Dopaminergic innervation of the striatum arises from which midbrain structure?
Select one:

a. Subthalamic nucleus
b. Substantia nigra pars compacta
c. Pedunculopontine nucleus
d. Substantia nigra pars reticulata

Answer 15

b. Substantia nigra pars compacta

Question 16

The Striatum receives afferent input from the:
Select one:

a. Cortex, substantia nigra and globus pallidus
b. Substantia nigra, habenula, and thalamus
c. Cortex, thalamus and substantia nigra
d. Thalamus, globus pallidus, and pedunculopontine nucleus

Answer 16

c. Cortex, thalamus and substantia nigra

Question 17

The corpus striatum comprises all of the following except the:

Select one:

a. Putamen
b. Globus pallidus
c. Amygdaloid body
d. Caudate nucleus

Answer 17

c. Amygdaloid body

Question 18

The striatum consists of which two nuclear masses?
Select one:

a. Putamen and globus pallidus
b. Caudate and globus pallidus
c. Caudate and putamen
d. Lentiform nucleus and subthalamic nuclei

Answer 18

c. Caudate and putamen