Basal Ganglia

Front 1

What makes up extrapyramidal system? (6)

Back 1

1)rubrospinal tract
2) lateral vestibulospinal tract
3) medullary reticulospinal tract
4) pontine reticulospinal tract
5) basal ganglia
6) tectospinal tract

Front 2

What are the components of the basal ganglia? (5)

Back 2

1)caudate nucleus
2) putamen
3) globus pallidus
4) subthalamic nucleus
5) substantia nigra

Front 3

What is the function of the basal ganglia?

Back 3

automated patterns of movement (walking, riding a bike, etc)

Front 4

What makes up the striatum? (2)

Back 4

1)caduate
2)putamen

Front 5

What is the lentiform nucleus?

Back 5

1) putamen
2) globus pallidus

Front 6

How do basal ganglia affect movement? (what is the loop)

Back 6

via the loop they have with motor cortex and motor thalamus
1) input: ipsilateral motor cortex
2) basal ganglia
3) output: motor thalamus (VA)
4) back to motor cortex (supplementary motor cortex M-II)

Front 7

What is the motor thalamus?

Back 7

VA and VL

Front 8

What parts of the basal ganglia are associated with their output?

Back 8

1) Internal segment of globus pallidus GPI
2) substantia nigra, pars reticulata SNr

Front 9

What is role of association cortex?

Back 9

planning and programming of movement

Front 10

What are the two substructures of the straitum? (microstructure)

Back 10

1) striosomes (patches)
2) matrix

Front 11

What is in the striosomes?

Back 11

D1 dopaminergic receptors which are the targets of nigrostraital

Front 12

What is in the matrix?

Back 12

D2 dopaminergic receptors which are targets of nigrostraital

Front 13

What are the two types of neurons in the straitum?

Back 13

1) spiny
2) aspiny

Front 14

What is more prevalent?

Back 14

spiny

Front 15

What is intrinsic vs extrinsic?

Back 15

spiny - extrinsic and long axon
aspiny - intrinsic and short axon

Front 16

Which are excitatory vs inhibitory? What type of neurotransmitter

Back 16

spiny - inhibitory GABAergic
aspiny - excitatory cholinergic

Front 17

Where do the spiny neurons go from the straitum?

Back 17

1)Globus Pallidus (straitopallidal)
2)Substantia nigra (straitonigral)

Front 18

What are the two inputs to the striatum?

Back 18

1)corticostraites (glut) +
2) dopaminergic nigrostraites +

Front 19

what is the suborganization of the corticostraites? (2)

Back 19

1)association cortex --> caudate
2) sensorimotor --> putamen

Front 20

What is the suborganization of the straitopallidals? (2)

Back 20

1) striosomes, D1, GpI -> Direct pathway to thalamus and then association cortex
2) matrix, D2 -> GpE, Indirectpathway through subthalamic nucleus back to GPi then to thalamus and association cortex

Front 21

What is the functional difference between the direct and indirect pathway?

Back 21

direct - facilitates movement
indirect - inhibits movement

Front 22

How does Huntington Disease relate to a disease of the basal ganglia? (2)

Back 22

huntington occurs when you have atrophy of the straitum and enlargement of the ventricles
as a result you get dance like hyperkinetic movements (chorea)

Front 23

Is Huntington's inherited?

Back 23

yes

Front 24

what is the pathway of how huntington's disease works (4)

Back 24

1)atrophy of straitum
2) less inhibition of GP
3) less tonic inhibition of motor thalamus
4) motor thalamus is excitatory on motor cortex

Front 25

What is ballism?

Back 25

hyperkinetic

Front 26

What is the major input to GP?

Back 26

gabaergics from straitum

Front 27

What are the two efferents of the GP?

Back 27

1)pallidothalamics via GPI (mostly VA)
2) pallidalsubtalamic via GPE

Front 28

Is pallidal efferents excitatory or inhibitory?

Back 28

inhibitory via gaba

Front 29

Suborganization of pallidothalamic efferents? (3)

Back 29

1)fasiculus l enticularis - cross intl capsule to get to thalamus
2) ansa lenticularis - go around the intl capsule
3)thalamic fasciculus = ansa lenticularis and fasiculus lenticularis going to motor thalamus/va

Front 30

Does subthalamus = subthalamic nucleus?

Back 30

no its just the biggest nucleus

Front 31

Is the subthalamic nucleus excitatory or inhibitory

Back 31

excitatory

Front 32

Lesion in subthalamic nucleus causes

Back 32

contralateral hemiballism

Front 33

What is a ballistic movement/ballism?

Back 33

large amplitude ballistic (missile??!) proximal limb movement

Front 34

What are the two hyperkinetic disorders?

Back 34

huntington's disease and hemiballism

Front 35

What are the two parts of the substantia nigra? how are they different?

Back 35

pars compacta- dopaminergic
pars reticulata - gaba-ergic

Front 36

Organization of afferents to substantia nigra?

Back 36

Afferents are from straitum and are inhibitory
1) striosomes,D1 - pars compacta (SNc)
2) matrix,D2 - pars reticulata (SNr)

Front 37

What is the efferents to the substantia nigra? (3)

Back 37

1)SnC- Dopaminergic- to straitum
2) SnR- Gaba - VA to motor thalamus
3) SnR - Gaba- superior colliculus (nigrotectal)

Front 38

What does the SNR do? (substantia nigra pars reticulata)

Back 38

tonically inhibit motor thalamus and superior colliculus

Front 39

What happens when SnR releases some inhibition on superior colliculus?

Back 39

saccadic eye movement

Front 40

How does Parkinsons disease relate to substantia nigra?

Back 40

caused by degeenration of dopaminergic neurons in pars compacta of SN

Front 41

What are the symptoms of parkinsons?

Back 41

1) resting tremor
2) bradykinesia
3) freezing gait
4) freezing (difficulty initiating movement)
5) rigidity
6) face like a mask

Front 42

What is intention tremor?

Back 42

cerebellar in movement

Front 43

What are treatments? (2)

Back 43

L dopa
deep brain stimulation

Front 44

What is mechanism of how parkinsons work?

Back 44

1) increased inhibition straitum
2) increased inhibition of motor thalamus
3) decreased excitation of motor cortex
4) hypokinetic movement

Front 45

What are the primary outputs from basal ganglia to motor thalamus (VA/VL)?

Back 45

1)GpI
2)SNr (pars reticulata)

Front 46

What is the pathway for the basal ganglia lesions?

Back 46

1) motor cortex
2) ipsilateral basal ganglia
3) pyramidal decussation/cross the midline through pyramidal tract
4) contralateral side of body

Front 47

Why is there a connection between basal ganglia disease and occulomotor deficits?

Back 47

Non-motor Occulomotor Loop
1)frontal eyefield cortex
2) caudate
3) GPi and Snr
4) mediodorsal and ventral thalamus
5) back to cortex

Front 48

Why is there a connection between cognitive deficiets and basal ganglia disease?

Back 48

Nonmotor-Prefrontal Loop
1)dorsalateral prefrontal cortex
2) anterior caudatae
3) Gpi and SNr
4) mediodorsal and ventral anterior nuclei of thalamus
5) cortex again

Front 49

Why is their relationship between occulomotor deficits and cognitive deficits?

Back 49

because Gpi and SNr dont just go to motor thalamus they also go to mediodorsal and ventral anterior nuclei of thalamus which then goes to prefrontal cortex/frontal eyefield