Basal Ganglia

Question 1

What is the overall purpose of the basal ganglia?

Answer 1

Important in making voluntary movements, postural adjustments. Receives input from cortex, and then provides feedback to cortex to modulate movement

Question 2

What is the striatum?

Answer 2

Receives input from cortex. Composed of Caudate (cognitive) and Putamen (motor).

Question 3

What is the lentiform part of the basal ganglia?

Answer 3

Putamen + globus pallidus

Question 4

What is the purpose of the “direct” pathway?

Answer 4

Excitatory

Question 5

What is the purpose of the “indirect” pathway?

Answer 5

Inhibitory

Question 6

What input does the thalamus give to cortex?

Answer 6

Excitatory

Question 7

What neurotransmitter does the substantia nigra pars compacta use?

Answer 7

dopamine

Question 8

Where are dopamine receptors in the basal ganglia?

Answer 8

Striatum. D2 in the INHIBITORY pathway, D1 in the DIRECT pathway.

Question 9

What is the effect of dopamine on D1 receptors? on D2 receptors? Overall?

Answer 9

Dopamine stimulates D1 receptors (excitatory pathway).
Dopamine inhibits D2 receptors, part of inhibitory pathway.
Overall, dopamine is excitatory.

Question 10

What is the direct pathway?

Answer 10

Cortex –> Striatum (stim)
Striatum —> GPi/SNr (inhibit)
Gpi/SNr –> Inhibs thalamus LESS
Thalamus –> excite cortex

Question 11

What is the role of the substantia pars compacta in the direct pathway?

Answer 11

Dopamine to D1 of striatum (stimulate).

Question 12

What is the indirect pathway?

Answer 12

Cortex --> striatum --> NEG to GPE
GPE inhibits STN LESS
STN excites Snr/GpI
SNR/Gpi inhibits Thalamus MORE
Thalamus excites cortex less