Olivocerebellar tract

Olivocerebellar tract
Transverse section of medulla oblongata below the middle of the olive. (Cerebello-olivary fibers visible at center right.)
Details
Identifiers
Latin	tractus olivocerebellaris
NeuroNames	804
NeuroLex ID	birnlex_1579
TA98	A14.1.04.118
TA2	5853
FMA	72638
Anatomical terms of neuroanatomy [edit on Wikidata]

The olivocerebellar tract, also known as olivocerebellar fibers, are neural fibers which originate at the olivary nucleus and pass out through the hilum and decussate with those from the opposite olive in the raphe nucleus, then as internal arcuate fibers they pass partly through and partly around the opposite olive and enter the inferior peduncle to be distributed to the cerebellar hemisphere of the opposite side from which they arise.

They terminate directly on Purkinje cells as the climbing fiber input system.^[1]

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

^ Eccles J.C, Llinas R, and Sasaki. Excitation of cerebellar Purkinje cells by the climbing fibers. Nature 203: 245-246, 1964

External links

Illustration and text: cere/text/p3/olivo.htm at the University of Wisconsin-Madison Medical school

Anatomy of the medulla

Grey matter

Cranial nuclei

afferent:	Solitary nucleus tract Dorsal respiratory group Gustatory nucleus Vestibular nuclei Lateral Medial Inferior
efferent:	Hypoglossal nucleus Nucleus ambiguus Dorsal nucleus of vagus nerve Inferior salivatory nucleus

Dorsal

Ventral

- Ventral respiratory group
- Arcuate nucleus of medulla
- Rostral ventromedial medulla
- Botzinger complex
- Pre-Bötzinger complex

White matter

Dorsal	Sensory Sensory decussation Medial lemniscus Juxtarestiform body Ascending dorsal longitudinal fasciculus Medial longitudinal fasciculus Motor Descending dorsal longitudinal fasciculus Medial longitudinal fasciculus
Ventral	Descending tracts Olivocerebellar tract Rubro-olivary tract

Surface

Front	Pyramid Anterior median fissure Anterolateral sulcus Olive Inferior olivary nucleus
Back	Posterior median sulcus Posterolateral sulcus Area postrema Vagal trigone Hypoglossal trigone Medial eminence Inferior cerebellar peduncle

Grey

Anatomy of the cerebellum

Surface

Lobes	Anterior lobe Posterior lobe Horizontal fissure Flocculonodular lobe Flocculus Nodule Primary fissure
Medial/lateral	Vermis: anterior Central lobule Culmen Lingula posterior Folium Tuber Uvula Vallecula of cerebellum Hemisphere: anterior Alar central lobule posterior Biventer lobule Cerebellar tonsil

Grey matter

Deep cerebellar nuclei	Dentate interposed Emboliform Globose Fastigial
Cerebellar cortex	Molecular layer Stellate cell Basket cell Purkinje cell layer Purkinje cell Bergmann glia cell = Golgi epithelial cell Fañanas cell Granule cell layer Golgi cell Granule cell Unipolar brush cell Fibers: Mossy fibers Climbing fiber Parallel fiber

White matter

Internal	Arbor vitae
Peduncles	Inferior (medulla): Dorsal spinocerebellar tract Olivocerebellar tract Cuneocerebellar tract Juxtarestiform body (Vestibulocerebellar tract) Trigeminocerebellar fibers Middle (pons): Pontocerebellar fibers Superior (midbrain): Ventral spinocerebellar tract Dentatothalamic tract

Brain and spinal cord: neural tracts and fasciculi

Sensory

DCML

1°:	Pacinian corpuscle/Meissner's corpuscle → Posterior column (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° (Spinomesencephalic 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

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 nuclei → 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 nuclei

Bidirectional:
Spinocerebellar

Unconscious proprioception	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)