Medial globus pallidus

Brain: Medial globus pallidus

Globus pallidus labeled at bottom right.

DA-loops in PD
Latin	Globus pallidus medialis
NeuroNames	hier-215

The medial globus pallidus (or internal, GPi) is one of the output nuclei of the basal ganglia (the other being the substantia nigra pars reticulata). The GABA-containing neurons send their axons to specific nuclei of the dorsal thalamus (VA and VL), to the centromedian complex and to the pedunculopontine complex.^[1]^[2]

The efferent bundle is constituted first of the ansa and fasciculus lenticularis, then crosses the internal capsule as the Edinger's comb system then arrives at the laterosuperior corner of the subthalamic nucleus and constitutes the Forel's field H2, then H, and suddenly changes its direction to form H1 that goes to the inferior part of the thalamus. The distribution of axonal islands is widespread in the lateral region of the thalamus. The innervation of the central region is done by collaterals.^[3]

References

^ Nauta WJ, Mehler WR (January 1966). "Projections of the lentiform nucleus in the monkey". Brain Res. 1 (1): 3–42. doi:10.1016/0006-8993(66)90103-X. PMID 4956247. http://linkinghub.elsevier.com/retrieve/pii/0006-8993(66)90103-X. Retrieved 2008-08-05.
^ Percheron G, François C, Talbi B, Meder JF, Fenelon G, Yelnik J (1993). "The primate motor thalamus analysed with reference to subcortical afferent territories". Stereotact Funct Neurosurg 60 (1–3): 32–41. doi:10.1159/000100588. PMID 8511432.
^ Yelnik J, François C, Percheron G, Tandé D (April 1996). "A spatial and quantitative study of the striatopallidal connection in the monkey". Neuroreport 7 (5): 985–988. doi:10.1097/00001756-199604100-00006. PMID 8804036.

Human brain, cerebrum, Interior of the cerebral hemispheres—Rostral Basal ganglia and associated structures (TA A14.1.09.321–552, GA 9.832–837)

Basal ganglia

Grey matter

Corpus striatum	striatum: Putamen · Caudate nucleus lentiform nucleus: Putamen · Globus pallidus (GPe, GPi)

Ventral striatum	Nucleus accumbens · Olfactory tubercle · Islands of Calleja

Other	Amygdala · Claustrum

White matter

Semioval center

Internal capsule (Anterior limb · Genu · Posterior limb, Optic radiation)

Corona radiata · External capsule · Extreme capsule

Pallidothalamic tracts: Thalamic fasciculus (Ansa lenticularis, Lenticular fasciculus) · Subthalamic fasciculus

Rhinencephalon

Grey matter	Anterior olfactory nucleus · Anterior perforated substance · Olfactory bulb

White matter	Olfactory tract (Medial olfactory stria, Lateral olfactory stria) · Olfactory trigone

Other basal forebrain

Grey matter	Substantia innominata (Basal optic nucleus of Meynert) · Nucleus of diagonal band

White matter	Diagonal band of Broca · Stria terminalis

Archicortex:
Hippocampal formation/
Hippocampus anatomy

Grey matter	Hippocampus proper: CA1 · CA2 · CA3 · CA4 Dentate gyrus: Fascia dentata Subiculum

White matter	Alveus · Fimbria · Perforant path · Schaffer collateral

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

Brain and spinal cord: neural tracts and fasciculi

Sensory/
ascending

PCML

1°: Pacinian corpuscle/Meissner's corpuscle → Gracile fasciculus/Cuneate fasciculus → Gracile nucleus/Cuneate nucleus

2°: → sensory decussation/arcuate fibers (Posterior external arcuate fibers, Internal arcuate fibers) → Medial lemniscus/Trigeminal lemniscus → Thalamus (VPL, VPM)

3°: → Posterior limb of internal capsule → Postcentral gyrus

Anterolateral/
pain

Fast/lateral	1° (Free nerve ending → A delta fiber) → 2° (Anterior white commissure → Lateral and Anterior Spinothalamic tract → Spinal lemniscus → VPL of Thalamus) → 3° (Postcentral gyrus) → 4° (Posterior parietal cortex) 2° (Spinotectal tract → Superior colliculus of Midbrain tectum)

Slow/medial	1° (Group C nerve fiber → Spinoreticular tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)

Motor/
descending

Pyramidal	flexion: Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral, Anterior) → Neuromuscular junction

Extrapyramidal	flexion: Primary motor cortex → Genu of internal capsule → Corticobulbar tract → Facial motor nucleus → Facial muscles flexion: Red nucleus → Rubrospinal tract extension: Vestibulocerebellum → Vestibular nuclei → Vestibulospinal tract extension: Vestibulocerebellum → Reticular formation → Reticulospinal tract Midbrain tectum → Tectospinal tract → muscles of neck

Basal ganglia	direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex) indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex) nigrostriatal pathway: Pars compacta → Striatum

Cerebellar

Afferent

Vestibular nucleus → Vestibulocerebellar tract → ICP → Cerebellum → Granule cell

Pontine nuclei → Pontocerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell

Inferior olivary nucleus → Olivocerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei

Efferent

Dentate nucleus in Lateral hemisphere/pontocerebellum → SCP → Dentatothalamic tract → Thalamus (VL) → Motor cortex

Interposed nucleus in Intermediate hemisphere/spinocerebellum → SCP → Reticular formation, or → Cerebellothalamic tract → Red nucleus → Thalamus (VL) → Motor cortex

Fastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nucleus

Bidirectional:
Spinocerebellar

Unc. prop.	lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis) upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneocerebellar tract → ICP → Anterior lobe of cerebellum)

Reflex arc	lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis) upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

M: PNS

anat(h/r/t/c/b/l/s/a)/phys(r)/devp/prot/nttr/nttm/ntrp

noco/auto/cong/tumr, sysi/epon, injr

proc, drug(N1B)

Medial globus pallidus

See also

References