Basal Ganglia & Motor Control

Question 1

what structures form the lentiform nucleus?

Answer 1

putamen
globus pallidus I (externum)
globus pallidus II (internum)

Question 2

what structures form the corpus striatum?

Answer 2

lentiform nucleus + caudate nucleus

Question 3

name the 2 subdivisions of substantia nigra

Answer 3

pars compacta
pars reticulata

Question 4

what structures form the ventral striatum?

Answer 4

head of caudate & putamen

Question 5

what neurotransmitter is released from substantia nigra pars compacta?

Answer 5

dopamine

Question 6

what neurotransmitter is released from substantia nigra pars reticulata?

Answer 6

GABA

Question 7

Name the 4 basal ganglia

Answer 7

lentiform
caudate
subthalamic
substantia nigra

Question 8

what is the most medial part of the ventral striatum?

Answer 8

nucleus accumbens

Question 9

the nigrostriatal pathway sends dopamine from ____ to the ____

Answer 9

• substantia nigra pars compacta
• basal ganglia

Question 10

the mesolimbic pathway sends dopamine from the ____ to the____

Answer 10

• ventral tegmental area
• parahippocampal gyrus & nucleus accumbens

Question 11

the mesocortical pathway sends dopamine from ____ to the ____

Answer 11

• substantia nigra & ventral tegmental area
• prefrontal cortex

Question 12

in the nigrostriatal pathway, the cerebral cortex projects to the ____ with ____ fibers

Answer 12

striatum
glutaminergic (+)

Question 13

in the direct pathway, substantia nigra pars compacta projects to the ____ with ____ fibers

Answer 13

striatum
dopaminergic (+)

Question 14

the striatum utilizes ____ interneurons for intercommunication

Answer 14

acetylcholinergic

Question 15

in the direct pathway, the striatum projects to the ____ and ____ with ____ fibers

Answer 15

globus pallidus I & substantia nigra pars reticulata
GABAergic (-)

Question 16

in the direct pathway, Globus pallidus I and substantia nigra pars reticulata project to the ____ with ____ fibers

Answer 16

ventral lateral & ventral anterior thalamic nuclei
GABAergic (-)

Question 17

in the direct pathway, what is the ultimate action on the thalamus?

Answer 17

thalamus gets excited because GPI is inhibited from inhibiting thalamus

Question 18

in the nigrostriatal pathway, the ventral anterior and ventral lateral thalamic nuclei project to the ____ with ____ fibers

Answer 18

supplementary & premotor cortex
glutaminergic (+)

Question 19

excitation of the direct pathway results in…

Answer 19

excitation of motor cortex and initiation of movement

Question 20

in the indirect pathway, substantia nigra pars compacta projects to the ____ with ____ fibers

Answer 20

striatum
dopaminergic (-)

Question 21

in the indirect pathway, the striatum projects to ____ with ____ fibers

Answer 21

globus pallidus II
GABAergic (-)

Question 22

in the indirect pathway, globus pallidus II projects to the ____ with ____ fibers

Answer 22

subthalamic nucleus
GABAergic (-)

Question 23

in the indirect pathway, the subthalamic nucleus projects to ____ with ____ fibers

Answer 23

globus pallidus I & substantia nigra pars reticulata
glutaminergic (+)

Question 24

in the indirect pathway, globus pallidus I & substantia nigra pars reticulata project to the ____ with ____ fibers

Answer 24

ventral lateral & ventral anterior thalamic nuclei
GABAergic (-)

Question 25

in the **indirect** pathway, what is the overall effect on the ventral anterior & ventral lateral thalamic nuclei

Answer 25

VA & VL are inhibited from projecting glutaminergic neurons to supplementary & premotor cortex

Question 26

excitation of the **indirect** pathway results in...

Answer 26

inhibition of motor cortex & stopping of movement

Question 27

Hypokinetic disorders involve breakdown of the ____

Answer 27

direct pathway

Question 28

Hyperkinetic disorders involve breakdown of the ____

Answer 28

indirect pathway

Question 29

symptoms of hypokinetic disorders

Answer 29

akinesia bradykinesia

Question 30

symptoms of hyperkinetic disorders

Answer 30

**dyskinesias** (involuntary movements): - chorea - ballismus - athetosis - dystonia

Question 31

what is the mechanism of Parkinson's disease?

Answer 31

depletion of dopaminergic cells in substantia nigra causing breakdown of nigrostriatal pathway

Question 32

symptoms of Parkinson's disease

Answer 32

- Akinesia (trouble starting movement) - Bradykinesia (slow voluntary movement) - Resting tremor - Cogwheel or lead pipe rigidity - Flexed posture - Mask-like facial expression - Shuffling & impaired balance

Question 33

Name 3 treatments of Parkinson's disease

Answer 33

1. L-DOPA precursor to dopamine 2. Human embryonic dopamine cell transplant (stem cells) 3. Pallidotomy (break globus pallidus I), GP I pacemakers, or thalamectomies

Question 34

What is Huntington's disease?

Answer 34

autosomal dominant hereditary disease with insidious onset in 4th-5th decade of life, resulting from slow degeneration of neurons in the striatum

Question 35

symptoms of Huntington's disease

Answer 35

- chorea (dance-like movements/involuntary twitching extremities & face) - dementia (cognitive deterioration) - behavioral or psychiatric disturbances

Question 36

prognosis of Huntington's disease

Answer 36

death 15-20 years after onset of disease

Question 37

Sydenham's chorea (St. Vitu's Dance)

Answer 37

transient (reversible) childhood chorea associated with rheumatic fever and affecting the striatum

Question 38

Athetosis

Answer 38

degeneration of globus pallidus resulting in slow, sinuous, writhing movements of distal extremities

Question 39

Ballism

Answer 39

lesion of subthalamic nucleus or its connections resulting in contralateral involuntary movements of proximal extremities & trunk

Question 40

Wilson's disease

Answer 40

autosomal recessive disorder that results in abnormal metabolism of copper which progressively degenerates the liver and basal ganglia

Question 41

Almost all patients with Wilson's disease present with...

Answer 41

a Kayser-Fleischer ring in their corneas & aberrant movements

Question 42

Dystonia Musculorum Deformans

Answer 42

rare hereditary condition associated with injury of lentiform nucleus, resulting in co-contraction

Question 43

examples of focal dystonias include...

Answer 43

torticollis (traps & SCM contract constantly) blepharospasm (upper eyelid spasm) dysphonia (vocal cord spasm) facial spasm writer's cramp