Basal Ganglia

Question 1

What are the components that make up the cerebellum?

Answer 1

1. Caudate
2. Putamen
3. Globus Pallidus
   - Internus (GPi)
   - Externus (GPe)
4. Substantia nigra
   - Pars compacta (SNpc)
   - Pars reticularis (SNpr)
5. Subthalamic Nuclei

Question 2

What 2 components make up the striatum?

Answer 2

Caudate and putamen

Question 3

What makes up the lenticulate nucleus?

Answer 3

Putamen and Globus Pallidus internus and externus

Question 4

What are the 2 brainstem components of the basal ganglia?

Answer 4

Substantia nigra and subthalamic nuclei

Question 5

Where is the subthalamic nuclei located?

Answer 5

In the midbrain-diencephalic junction

Question 6

What is the function of the basal ganglia?

Answer 6

Motor control!

Question 7

What are the 3 ways the basal ganglia helps with motor contol?

Answer 7

1. Initiation and execution of movement.
   - Helps with regulation of muscle contraction, muscle force, multi-joint movement, and sequencing of movement.
2. Prevention of unwanted movements through inhibitory control.
3. Direct and indirect pathways that work together to help create desired movement.

Question 8

What structure receives all input for the basal ganglia?

Answer 8

The striatum

Question 9

Where does the caudate receive input from?

Answer 9

1. Heteromodal association cortices

2. Motor areas of frontal lobe involved in eye movements.

Question 10

Where does the putamen receive input from?

Answer 10

1. 1 and 2 order sensory cortices in prietal lobe
2. Higher order visual cortices in occipital and temporal lobes
3. Premotor cortex and PriMC
4. Auditory association cortices temporal lobe.

Question 11

What are 3 other structures that send input to the striatum?

Answer 11

1. SNpc
2. Intralaminar nuclei of thalamus
3. Subcortical structures about modulatory input from NT systems.

Question 12

What are the 2 cortices that DO NOT send input to the basal ganglia?

Answer 12

The primary visual and primary auditory cortices.

Question 13

What are the two structures in charge on basal ganglia output?

Answer 13

The globus pallidus internus and the stubstantia nigra pars reticularis.

Question 14

What locations do the ventral lateral and ventral anterior nuclei project output from the basal ganglia?

Answer 14

Project on to the entire frontal lobe –> PriMC, premotor area, and supplementary motor area.

Question 15

What does the intralaminar nuclei of the thalamus send output for from the basal ganglia?

Answer 15

It projects for additional motor relay.

Question 16

What does the mediodorsal nucleus project output for?

Answer 16

For the limbic basal ganglia loop.

Question 17

What does the superior colliculus receive output information for?

Answer 17

For the eye movement basal ganglia loop.

Question 18

What does the direct pathway of the basal ganglia control?

Answer 18

Controls the start/initiation of movement.

Question 19

What does the indirect pathway of the basal ganglia control?

Answer 19

Controls the inhibition of movement.

Question 20

What region of the basal ganglia regulates the direct and indirect pathways by releasing dopamine?

Answer 20

The substantia nigra pars compacta.

Question 21

What is the function of the Substantia Nigra Pars Compacta? What type if input is it for both pathways?

Answer 21

Modulates striatum activity through dopamine release to impact the direct and indirect pathways.

Excitatory to striatum in direct pathway.
Inhibitory to striatum in indirect pathway.
Effect = powerful decrease in suppression of thalamus by basal ganglia.

Question 22

What is the action of acetylcholine in the basal ganglia?

Answer 22

Inhibits dopamine when appropriate and can quickly interrupt ongoing motor behavior in response to salient environmental stimuli.

Question 23

What are the 2 neurotransmitters involved in the direct and indirect pathways?

Answer 23

GABA and Glutamate

Question 24

What does the oculomotor loop of the basal ganglia control?

Answer 24

Higher control of eye movements.

Aids in spatial attention; initiates fast eye movements toward an object (saccadic movement)

Question 25

What are the pre-frontal loops of the basal ganglia and what do they control?

Answer 25

1. Goal-directed behavior loop = via GPi = decision making; goal directed behavior; planning; action selection; learning
2. Social behavior loop = via SNpr = recognizes social cues; regulate self control; evaluates what information is relevant and irrelevant.

Question 26

What is the limbic/emotion loop of the basal ganglia control?

Answer 26

Links emotions to cognitive and motor systems; reward seeking; outcome predictions

*receives dopaminergic input from the ventral tegmental area.