Basal Ganglia

Question 0

What are the four nuclear masses associated with the basal ganglia?

Answer 0

Corpus striatum, globus pallidus, substantia nigra, and subthalamic nuclei

Question 1

Describe how information is relayed to and from the basal ganglia.

Answer 1

Basal ganglia receives information from the cerebral cortex and sends information to the thalamus and the brainstem

Question 2

What are the two structures associated with the corpus striatum?

Answer 2

Caudate and putamen

Question 3

What is the function of the basal ganglia?

Answer 3

Modulate the output of descending motor systems and govern the initiation and cessation of movement

Question 4

What is the function of the caudate nucleus?

Answer 4

Important in learning and memory functions and feedback processing

Question 5

What is the caudate nucleus innervated by?

Answer 5

Dopamine neurons

Question 6

What is the cofunction of the caudate and putamen?

Answer 6

Receive information from the descending pathways (specifically the lateral corticospinal tract) and innervate ipsilateral globus pallidus via GABA (Gamma aminobutyric acid) fibers

Question 7

What are the two types of caudate and putamen neurons?

Answer 7

Principal neurons and local circuit neurons

Question 8

What are the three types of hyperkinetic states that are caused by lesions from the caudate and putamen neurons?

Answer 8

1. Chorea - rapid, jerky movements
2. Athetosis - slow, sinus movements
3. Dystonia - slow, sustained movements

Question 9

Restricted to just the putamen, what do the lesions result in?

Answer 9

Motor dysfunction in contralateral limbs

Question 10

Restricted to just the caudate, what do the lesions result in?

Answer 10

Behavioral defects

Question 11

What type of impairment results from lesions to the globus pallidus?

Answer 11

Hypokinesia - similar to Parkinsonian rigidity

Question 12

What type of impairment results from lesions to the substantia nigra?

Answer 12

Parkinsonian signs and symptoms in the contralateral side of the body

Question 13

What part of the basal ganglia is associated with the production of dopamine?

Answer 13

Substantia nigra

Question 14

What is the input connection to the basal ganglia?

Answer 14

All regions of the cerebral cortex project to the basal ganglia

Question 15

What is the output connections from the basal ganglia?

Answer 15

Basal ganglia is directed towards the frontal lobe, particularly the pre-motor and supplementary motor cortex

Question 16

What part of the basal ganglia is the main recipient of input to the basal ganglia?

Answer 16

Striatum (caudate and putamen)

Question 17

What are the two parts of the basal ganglia that deal with output?

Answer 17

Globus pallidus interna and substantia nigra pars reticulata

Question 18

Are output pathways regarding the basal ganglia inhibitory or excitatory?

Answer 18

Inhibitory

Question 19

What are the three neurotransmitters involved in the basal ganglia circuit and what type are they?

Answer 19

1. Glutamate - excitatory
2. GABA - inhibitory
3. Dopamine - excitatory in direct pathway and inhibitory in indirect pathway

Question 20

What are the two types of pathways and what type are they?

Answer 20

1. Direct - excitatory

2. Indirect - inhibitory

Question 21

What are the four parallel channels through the basal ganglia?

Answer 21

Motor channel, oculomotor channel, prefrontal channel, and the limbic channel

Question 22

What are two types of disorders caused by basal ganglia impairments?

Answer 22

1. Hypokinetic disorders - Parkinson’s (excessive inhibition from the BG)
2. Hyperkinetic disorders - Huntington’s (inadequate inhibition from the BG)

Question 23

What is a common characteristic of Parkinson’s and what is it caused by?

Answer 23

Muscular rigidity - caused by degeneration of dopamine neurons in the substantia nigra

Question 24

What is a common characteristic of Huntington’s and what is it caused by?

Answer 24

Involuntary continuous movements - too much excitation by BG