Neuroanatomy - Corpus Striatum - Crossman + Neary

Front 1

Is the amygdala part of the basal ganglia?

Back 1

No. it has a similar embryological development but is part of the lybic system

Front 2

The caudate nucleus, (globus pallidus) and putamen are collectively referred to as the...?

Back 2

corpus striatum

Front 3

the putamen and globus pallidus are referred together as the...?

Back 3

lentiform nucleus

Front 4

What structures form the striatum?

Back 4

putamen + caudate nucleus

Front 5

What structures does the putamen lie lateral to?

Back 5

internal capsule and globus pallidus

Front 6

what structure(s) separate the globus palidus form the putamen?

Back 6

lateral medullary lamina

Front 7

What structure lies lateral to the putamen and is sandwiched between two sheets of white matter?

Back 7

claustrum

Front 8

What are the two devisions of white matter separated by the claustrum?

Back 8

external capsule and extream capsule.

Front 9

What are the two anatomical parts of the caudate nucleus?

Back 9

large head and tapering curved tail

Front 10

What lies between the caudate nucleus and the putamen?

Back 10

the internal capsule

Front 11

what is the nucleus accumbens?

Back 11

the most ventral part of the striatum where putamen and caudate nucleus are continuous

Front 12

What is the substantia innominata?

Back 12

basal part of the rostral forebrain lies beneath the corpus striatum

Front 13

What are the three principle sources of striatal afferents?

Back 13

cerebral cortex, substantia nigra and thalamus

Front 14

Where do corticostriatal fibers originate?

Back 14

cerebral cortex, principally the ipsilateral side, principally frontal and parietal lobes

Front 15

In the corticostriatal fibres where do fibres from the motor regions of the fontal lobe project to? how are they arranged?

Back 15

The putamen. inverted somatotopic fashion.

Front 16

What is the more overtly motor part of the striatum?

Back 16

Putamen

Front 17

In corticostriatal fibres where do the more anterior and parts of the frontal lobe and other associated cortex project to?

Back 17

Caudate nucleus

Front 18

What neurotransmitter do corticostriatal fibres use? are they excitatory or inhibitory?

Back 18

Glutamate - excitatory

Front 19

Where does the thalamostriatal projection come from?

Back 19

ipsilateral intralaminar nuclei of the thalamus

Front 20

Where does the nigrostriatal projection originate from?

Back 20

pars compacta of the ipsilateral substantia nigra of midbrain tegmentum

Front 21

Is dopamine in the nigrostriatal projection inhibitory or excitatory?

Back 21

Both

Front 22

What is the dark pigment in the nigrostriatal pathway?

Back 22

neuromelanin-byproduct of dopamine synthesis?

Front 23

Where does the nucleus accumbens receive its dopaminergic pathway from?

Back 23

Ventral tegmental area - in the mesostriatal pathway

Front 24

What part of the brain steam projects to the striatum?

Back 24

raphe nuclei

Front 25

What are the two main striatal efferent pathways/where do they go?

Back 25

striatopallidal to the two segements of the globus pallidus and the striatonigral to the pars reticulata of the substantia nigra

Front 26

What cells are the origin of striatal efferents?

Back 26

spiny neurones

Front 27

What is the main cell type of striatal N. cells

Back 27

spiny neurones

Front 28

What is striatal efferent N.'s main neurotransmitter?

Back 28

GABA therefor inhibitory

Front 29

Other than GABA what neurotransmitters do neurones to the substantia nigra and medial segment of the globus pallidus contain?

Back 29

Substance P and dynorphin

Front 30

Other than GABA what neurotransmitters do neurones to the lateral segment of the globus pallidus contain?

Back 30

met-enkephalin

Front 31

What is regarded as the "output" part of the basal ganglion?

Back 31

medial segment of the globus pallidua and the pars reticulata

Front 32

Where to Pallidal afferents principally arise from?

Back 32

subthalamic nucleus and the striatum

Front 33

Which part of the globus pallidus does the subthalamopallidal projection run to?

Back 33

both though more dense in the medial part

Front 34

What neurotransmitter does the subthalamopallidal pathway uses?

Back 34

Glutamate so is excitatory to pallidal neurons

Front 35

Other than the globus pallidus where else in the basal ganglia does the subthalamic nucleus send efferents?

Back 35

Pars reticulata of the substantia nigra.

Front 36

Where is the main efferents of the lateral segment of the globus pallidus? What neurotransmitter?

Back 36

the subthalamic nucleus - GABA so therefor inhibatory

Front 37

Where is the main efferents of the, medial segment of the globus pallidus? What neurotransmitter?

Back 37

With the pars reticulata it passes to the thalamus (ventral lateral, ventral medial and centromedian nuclei) - GABA so therefor inhibatory

Front 38

What are the two ways pallidothalamic fibres reach the thalamus?

Back 38

some round the anterior margin of the internal capsule ansa lenticularis, others though the internal capsule as the lenticular fasciculus

Front 39

What pathway contributed the main outflow of the basal ganglia?

Back 39

pallidothalamic pathway

Front 40

The ventral anterior and ventral lateral nuclei of the thalamus receive pallidothalamic fibres, but where do they run?

Back 40

motor regions of frontal lobe (primary motor and supplementary motor cortices)

Front 41

a small contingent of the medial pallidal efferents leave to go to the the brain steam terminating at the boundary between the pons and midbrain, whats the name of it destination?

Back 41

Nucleus tegmenti pedunculopontinus.

Front 42

What part of the corpus striatum is the pars reticulata considered to be a part of?

Back 42

medial globus palidus

Front 43

How are motor fibres from the striatum organised in the pars reticulata?

Back 43

somatotopically organised

Front 44

What type of movement are pallidal neurones associated with?

Back 44

Limb movement.

Front 45

What type of movement are the pars reticulata concerned with?

Back 45

axial and eye movement.

Front 46

To which colliculus does the pars reticulata project to?

Back 46

Superior colliculus.

Front 47

What are the current concepts of the basal ganglia?

Back 47

facilitate movement and behaviour required or appropriate, but to inhibit inappropriate.

Front 48

How does the cerebral cortex join to the striatum?

Back 48

As well as projecting in corticospinal and corticobulbar also corticostriatal projectins to striatum

Front 49

What are the two ways in which the striatum can influence output from the medial segment of the globus pallidus and pars reticulata? Describe them?

Back 49

Direct pathway=striatopallidal/striatonigral fibers directly inhibit medial pallidal or pars reticulata neurons. As these are also inhibitory neurones there is a decrease in inhibition of respective target neurones, including motor thalamic neurones leading the excitation of cells in the cerebral cortex>supporting ongoing movements
Indirect pathway (via subthalamic neurons)= striatum to lateral globus pallidus which it inhibits, then to subthalamic nucleus which is disinhibited, this then cause excitation of medial pallidal and pars retiulata neurones, inhibition of thalamic and cortical cells, inhibiting unwanted movements.

Front 50

What effects does dopamine have on the striatal direct and indirect pathways? How does this change in Parkinson's?

Back 50

direct = excitatory (normally lead to increased stimulation of the cortex, in parkinson decreased stimulation of the cortex)
indirect = inhibitory (normally decreases stimulation of thalamus, but in Parkinson's it increases inhibition of the cortex)

Front 51

What is the effect of Huntington's on the basal ganglia?

Back 51

attrition of pathways going to lateral segment of the globus pallidus (indirect)>disinhibition of lateral globus pallidus>inhibition of subthalamic nucleus>medial segment of globus pallidus under-active>involuntry movement ensue.

Front 52

What is the effect of Huntington's on the basal ganglia?

Back 52

attrition of pathways going to lateral segment of the globus pallidus (indirect)>disinhibition of lateral globus pallidus>inhibition of subthalamic nucleus>medial segment of globus pallidus under-active>involuntry movement ensue.