Lecture 12: The Basal Ganglia

Question 1

The Basal Ganglia mainly participated in the control of what?

Answer 1

Movement.

Question 2

Other than movement, what does the basal ganglia also play a role in?

Answer 2

Cognition, emotion and eye movements.

Question 3

Are the structures of the basal ganglia unilateral or bilateral?

Answer 3

Bilateral.

Question 4

What are the structures of the basal ganglia?

Answer 4

Striatum (which consists of the caudate nucleus, putamen and nucleus accumbens)
Subthalamic nucleus
Globus pallidus (which consists of an internal and external segment)
Substantia nigra (which consists of the pars compacta and pars reticulata)

Question 5

Which structures are the input nuclei of the basal ganglia?

Answer 5

The striatum:

• caudate nucleus
• putamen

Question 6

Which structures are the output nuclei of the basal ganglia?

Answer 6

• Internal segment of globus pallidus

- Substantia nigra pars reticulata

Question 7

Which structures are the intrinsic nuclei of the basal ganglia?

Answer 7

• Subthalamic nucleus
• External segment of globus plallidus
• Substantia nigra pars compacta

Question 8

What are the two different types of striatal neurons?

Answer 8

Projection neurons and

Interneurons

Question 9

Do projection neurons or interneurons make up 90% of striatal neurons?

Answer 9

Projection neurons.

Question 10

Projection neurons are known as?

Answer 10

Medium spiny neurons (MSN)

Question 11

Does the striatum receive excitatory or inhibitory input from the cerebral cortex?

Answer 11

Excitatory (glutamate)

Question 12

Are medium spiny neurons excitatory or inhibitory?

Answer 12

Inhibitory, they are GABAergic.

Question 13

Where does the subthalamic nucleus receive excitatory input from?

Answer 13

The frontal cortex. But it is not counted as an input nucleus because the pathway is a lot smaller than those of the input nuclei.

Question 14

Where does the subthalamic nucleus receive inhibitory input from?

Answer 14

The external segment of the globus pallidus.

Question 15

The Substantia nigra pars compacta and the external segment of the globus pallidus receive input from where?

Answer 15

The striatum:

The caudate nucleus and the putamen.

Question 16

Where does the globus pallidus external receive inhibitory input from?

Answer 16

The striatum.

Question 17

Where does the globus pallidus external receive excitatory input from?

Answer 17

The subthalamic nucleus.

Question 18

Does the globus pallidus external provide excitatory or inhibitory input to other basal ganglia structures?

Answer 18

Inhibitory.

Question 19

What is the neurotransmitter of the Substantia nigra pars compacta?

Answer 19

Dopamine.

Question 20

Substantia nigra pars compacta dopaminergic neurons project back to where?

Answer 20

The striatum. It is a modulatory dopamine projection.

Question 21

Where do the large neurons or the globus pallidus internal primarily project to?

Answer 21

The thalamus.

Question 22

The globus pallidus internal receives input via two pathways, what are they and where are they from?

Answer 22

The direct pathway: input directly from the striatum.

The indirect pathway: inputs go via the subthalamic nucleus and the globus pallidus external.

Question 23

Where do the large neurons of the Substantia nigra pars reticulata primarily project to?

Answer 23

The thalamus.

Question 24

Is the direct pathway that provides input to the globus pallidus internal from the striatum excitatory or inhibitory?

Answer 24

Inhibitory.

Question 25

What does damage to the basal ganglia do?

Answer 25

Causes involuntary movements and postures and causes slowness of voluntary movement.

Question 26

Degeneration of the Substantia nigra pars compacta is associated with what disease?

Answer 26

Parkinson’s disease.