Basal Nuclei Anatomy

Question 1

Compared to the basal nuclei, where does the internal capsule run?

Answer 1

Lateral to caudate, medial to putamen and globus pallidus

Question 2

What are four movement disorders related to the basal nuclei?

Answer 2

Parkinson’s (poverty of mvmt), dystonia (slow, sustained mvmt), Huntington’s (jerky, uncontrollable mvmt), hemiballism (violent, uncontrollable mvmt)

Question 3

What are the motor functions of the basal nuclei?

Answer 3

Modulate pyramidal motor system (corticospinal, corticobulbar); initiation and programming mvmt, generation and timing mvmt, automatic and learned mvmt

Question 4

What are other functions (not motor) of basal nuclei?

Answer 4

Reward/addiction, depression, OCD, anorexia nervosa, learning/attention, SZ, Tourette’s

Question 5

What do pontocerebellum and basal nuclei have in common?

Answer 5

Modulate intended movement, input from cortex (BN direct, PC indirect via pons), feedback indirectly to motor cortex via VL/VA

Question 6

What are differences between pontocerebellum and basal nuclei?

Answer 6

BN: initiation/programming of voluntary mvmt, unilateral lesion -> contra
PC: coordination voluntary mvmt, unilateral lesion -> ipsi (intention tremor, dysmetria)

Question 7

What is the blood supply to the corpus striatum?

Answer 7

Lenticulostriate aa off M1

Question 8

What is the blood supply to the substantia nigra and subthalamic nuc?

Answer 8

Thalamoperforate aa off P1

Question 9

What makes up the dorsal and ventral striatum?

Answer 9

Dorsal: caudate, putamen
Ventral: nucleus accumbens, etc.

Question 10

What is the dorsal pallidum?

Answer 10

Globus pallidus

Question 11

What are the non-telencephalic modulators of the basal nuclei?

Answer 11

Mesencephalon: substantia nigra, ventral tegmental area, mesencephalic motor area
Diencephalon: subthalamic nuc

Question 12

To where does the internal globus pallidus project?

Answer 12

VA/VL and PPtN (mes motor area)

Question 13

What is the significance of the SN pars compacta?

Answer 13

DA cell bodies, projects DA to dorsal striatum, degenerates in PD

Question 14

What is the SN pars reticulata?

Answer 14

GABA neurons, input from dorsal striatum, output to regulate pars compacta, inhibit eye mvmts

Question 15

How does the SN pars reticulata regulate saccadic eye movements?

Answer 15

Inhibits superior colliculus, with internal globus inhibits frontal eye fields

Question 16

How are saccadic eye movements affected in PD and HD?

Answer 16

Decreased in PD bc reticulata and int globus fire excessively; increased in HD bc both don’t fire

Question 17

What are the functions of the subthalamic nucleus?

Answer 17

Promotes rhythmic movements like walking, also projects to SN

Question 18

What does a stroke of the thalamoperforate a case?

Answer 18

Hemiballism (violent, non-rhythmic mvmts) bc subthalamic nucleus affected

Question 19

What does the PPtN/mes motor area do?

Answer 19

Basic motor programs, like walking

Question 20

How does the direct pathway affect movement? Indirect pathway? What happens when there is too much of either?

Answer 20

D: stimulates movement (too much = dyskinesia)
I: inhibits movement (too much = bradykinesia, as in PD)

Question 21

What NT is used in dorsal striatum, internal GP, external GP?

Answer 21

GABA GABA GABA

Question 22

What NT is released from SN pars compacta? From subthalamic nucleus?

Answer 22

SNPC: dopamine
STN: glutamate

Question 23

What are D1 and D2 receptors?

Answer 23

DA receptors
D1: excitatory
D2: inhibitory