Flashcards in export_basal ganglia Deck (39)
What are the components of the basal ganglia
1. Corpus striatum - neostriatum and paleostriatum
3. Subthalamic nucleus
4. Substantia nigra
Caudate and putamen
Corpus Striatum =
Neo and paleostriatum
= Caudate, putamen and basal ganglia.
Lentiform nuclei =
Putamen and globus pallidus
Diencephalic nucleus =
Paleostriatum and subthalamic nucleus
Telencephalic nucleus =
Neostriatum and archistriatum
What are the components of the caudate nucleus
1. Head - contiguous with the APF
2. Body - separated from the thalamus by the stria terminalis and the terminal vein
3. Tail - In the roof of the temporal horn near the amygdala
4. Nucleus Accumbens - located where the caudate and putamen meet anteriorly
Which fibers/tracts send input to the striatum
5. Raphe nucleus
1. Area 4 to the bilateral putamen
2. Premotor cortex to the ipsilateral caudate and putamen
3. Prefrontal cortex to the caudate
Amygdala to the caudate and putamen.
1. Intralaminar CM nucleus to the putamen
2. Parafascicular nucleus to the caudate
Substantia nigra to the caudate and the putamen. Transmits inhibitory dopaminergic signals.
Raphe nucleus input to the striatum
Transmits inhibitory serotonergic signals to the striatum.
What are the three major striatal output fibers?
Striatonigral fibers ouput:
Head of the caudate to the substantia nigra pars reticulata.
Striatopallidal fibers output:
Inhibitory/GABA output from the caudate/putamen to the globus pallidus interna.
Nigrothalamic fibers output:
Terminate in the VA, VL, MD fibers. Use GABA as neurotransmitters.
What are the three medullary lamina
1. Lateral medullary lamina lies between the putamen and the globus pallidus
2. Medial medullary lamina - divides the medial and lateral GP
3. Accessory medullary lamina - divides the MGP into the inner and outer segments.
Input to the globus pallidus
Striatum to the LGP - GABA/enkephalin
Striatum to the MGP - Substance P
Lateral part of the subthalamus reciprocal glutamergic input to the LGP.
Medial part of the subthalamus reciprocal glutamergic input to the MGP
Which neurotransmitters are decreased in Huntington's disease and to which regions.
Substance P and enkephalin.
Globus Pallidus and substantia nigra.
What are the four output bundles/tracts from the globus pallidus.
1. Ansa lenticularis
2. Lenticular fasciculus
3. Thalamic fasciculus
4. Pallidosubthalamic fibers.
Features of the ansa lenticularis
Major output tract of the globus pallidus
From the MGP around the IC to Forel's field H1 - FFH1 - and the prerubral field.
Features of the lenticular fasciculus
Also known as FFH2 fibers.
They pass from the MGP through the IC to join the ansa lenticularis in Forel's field and then enters the thalamic fasciculus.
Features of the thalamic fasciculus
Also known as the FFH1 fibers.
This bundle is composed of the joined ansa lenticularis, lenticular fasciculus, and cerebellothalamic tract which all project to the thalamic VA and VL.
Features of the pallidosubthalamic fibers
1. LGP to the subthalamus
2. MGP to the stria medularis and lateral habenulum
3. GP to the VA, VL and CM.
Where is the subthalamus located?
Posterolateral to the hypothalamus, ventral to the thalamus and medial to the internal capsule - lesions here cause contralateral hemiballismus
What are some key components of the subthalamic nucleus
1. Subthalamic nuclei of Luys - located over the rostra SN
2. Zona incerta - grey matter between the thalamic and lenticular fasciculi. Motor input
3. Sensory fasciculi - medial lemniscus, spinothalamic, and trigeminothalamic tracts --> VP thalamus
4. Cerebellar and globus pallidus fibers which run to the thalamus.