Corticopontine fibers

Projections from the cerebral cortex to the pontine nuclei

Corticopontine fibers

Coronal section through mid-brain.
1\. Corpora quadrigemina.
2\. Cerebral aqueduct.
3\. Central gray stratum.
4\. Interpeduncular space.
5\. Sulcus lateralis.
6\. Substantia nigra.
7\. Red nucleus of tegmentum.
8\. Oculomotor nerve, with 8’, its nucleus of origin. a. Lemniscus (in blue) with a’ the medial lemniscus and a" the lateral lemniscus. b. Medial longitudinal fasciculus. c. Raphé. d. Temporopontine fibers. e. Portion of medial lemniscus, which runs to the lentiform nucleus and insula. f. Cerebrospinal fibers. g. Frontopontine fibers.

Details
Identifiers
Latin| fibrae corticopontinae, tractus corticopontinus
NeuroNames| 1322
TA98| A14.1.05.107
TA2| 5619
FMA| 75190
Anatomical terms of neuroanatomy

[edit on Wikidata]

Corticopontine fibers are projections from layer V of the cerebral cortex to the pontine nuclei of the ventral pons.[1] They represent the first link in a cortico-cerebello-cortical pathway mediating neocerebellar control of the motor cortex. The pathway is especially important for voluntary movements.[2]

Depending upon the lobe of origin, they can be classified as frontopontine fibers, parietopontine fibers, temporopontine fibers or occipitopontine fibers. Fibers from the frontal lobe and the parietal lobe are more numerous. [2]

## Anatomy

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### Origin

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All corticopontine fibers arise from pyramidal neurons in layer V of the cerebral cortex. They include fibers of the premotor, somatosensory, extrastriate, posterior parietal, and cingulate cortices; there are also a few fibers originating from the prefrontal, temporal, and striate cortex.[3]

The corticopontine system contains a number of fibers from different areas of the cortex, and are far more numerous in total than the corticospinal fibers.[4] Corticopontine fibers include:

* Frontopontine fibers that arise from the frontal lobe and are found in the medial third of the crus cerebri[5]
* Parietopontine fibers that arise from the parietal lobe and found in the lateral part of the crus cerebri [5]
* Occipitopontine fibers that arise from the occipital lobe and found in the lateral part of the crus cerebri [5]
* Temporopontine fibers arising from the temporal lobe are also found in the lateral part of the cerebral crus [5]

### Course

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All the fibers from the corticopontine system terminate in the pontine nuclei. The fibers descend through the sublenticular and retrolenticular of internal capsule, then traverse the midbrain through the basis pedunculi (i.e. ventral part of cerebral peduncle) to reach the pontine nuclei and synapse with neurons that give rise to pontocerebellar fibers.[2]

As the corticopontine fibres descend in the cerebral peduncle, those from the prefrontal regions are situated most medially; those from premotor and motor cortices are situated in the middle third of the peduncle, and fibers from the parietal, temporal and occipital regions that travel to the pons are in the lateral third of the cerebral peduncle.[3]

Two fiber bundles, an anterior and a posterior bundle relate the cortex to the cerebellum. The anterior bundle, is of frontopontine fibers, particularly from Brodmann areas 4 and 6 and is known as Arnold's bundle. The posterior bundle is of the corticopontine fibers comprising the parietopontine, temporopontine, and occipitopontine fibers, and is known as Türck's bundle.[6] [7]

## References

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1. ^ Rahman, Masum; Tadi, Prasanna (2024). "Neuroanatomy, Pons". StatPearls. StatPearls Publishing. Retrieved July 26, 2024.
2. ^ a b c "corticopontine fibres - Dictionnaire médical de l'Académie de Médecine". www.academie-medecine.fr. Retrieved July 27, 2024.
3. ^ a b Standring, Susan (2016). Gray's anatomy: the anatomical basis of clinical practice. Digital version (41st ed.). Philadelphia, Pa.: Elsevier. p. 479\. ISBN 9780702052309.
4. ^ Standring, Susan (2016). Gray's anatomy: the anatomical basis of clinical practice. Digital version (41st ed.). Philadelphia, Pa.: Elsevier. p. 434\. ISBN 9780702052309.
5. ^ a b c d Haines, Duane E.; Mihailoff, Gregory A. (2018). Fundamental neuroscience for basic and clinical applications (5th ed.). Philadelphia: Elsevier. p. 186\. ISBN 9780323396325.
6. ^ Standring, Susan (2016). Gray's anatomy: the anatomical basis of clinical practice. Digital version (41st ed.). Philadelphia, Pa.: Elsevier. p. 538\. ISBN 9780702052309.
7. ^ Engelhardt, E (2013). "Cerebrocerebellar system and Türck's bundle". Journal of the History of the Neurosciences. 22 (4): 353–65. doi:10.1080/0964704X.2012.761076. PMID 23789971.

## External links

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* https://www.csuchico.edu/~pmccaffrey/syllabi/CMSD 320/362unit7.html

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Anatomy of the pons

Dorsal/
(tegmentum)|

| Surface|

* Cerebellopontine angle
* Superior medullary velum
* Sulcus limitans
* Medial eminence
* Facial colliculus

|

White: Sensory|

* Trapezoid body
* Trigeminal lemniscus
* Dorsal trigeminal tract
* Ventral trigeminal tract
* Medial lemniscus
* Lateral lemniscus
* Central tegmental tract
* Medial longitudinal fasciculus
* Vestibulo-oculomotor fibers

White: Motor|

* Inferior cerebellar peduncle
* Vestibulocerebellar tract
* Medial longitudinal fasciculus
* Vestibulospinal tract
* Medial vestibulospinal tract
* Lateral vestibulospinal tract

Grey: Cranial nuclei|

| afferent:|

* GSA
* Trigeminal
* Principal
* Spinal
* Cochlear nucleus
* Dorsal
* Anterior
* Vestibular nuclei
* Superior

|

efferent:|

* SVE: Trigeminal motor nucleus
* Facial motor nucleus
* GSE: Abducens nucleus
* GVE: Superior salivary nucleus
* Inferior salivary nucleus

Grey: Other nuclei|

* Pedunculopontine nucleus
* Apneustic center
* Pneumotaxic center
* Parabrachial nuclei
* Subparabrachial nucleus
* Medial parabrachial nucleus
* Lateral parabrachial nucleus
* Superior olivary nucleus
* Locus coeruleus

Ventral/
(base)|

| Grey|

* Pontine nuclei

|

White: Motor/descending|

* Corticospinal tract
* Corticobulbar tract
* Corticopontine fibers
* MCP
* Pontocerebellar fibers

Surface|

* Basilar sulcus

Other grey: Raphe/
reticular|

* Reticular formation
* Caudal
* Oral
* Tegmental
* Paramedian
* Raphe nuclei
* Median

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Anatomy of the midbrain

Tectum
(Dorsal)|

| Corpora quadrigemina|

* Inferior colliculus
* Inferior brachium
* Superior colliculus
* Superior brachium

|

Grey matter|

* Pretectal area

White matter|

| Sensory / ascending|

* Spinotectal tract
* Central tegmental tract

|

Motor / descending|

* Tectospinal tract

CSF|

* Cerebral aqueduct

Peduncle
(Ventral)|

| Tegmentum|

| White matter|

| Sensory / ascending|

* Lemnisci
* Medial
* Lateral
* Ascending MLF
* Vestibulo-oculomotor fibers
* Spinothalamic tract
* Ventral trigeminal tract
* Dentatothalamic tract

|

Motor / descending|

* Rubrospinal tract
* Rubro-olivary tract
* Descending MLF

Grey matter|

| cranial nuclei|

* GSA
* Mesencephalic
* GSE
* Oculomotor nucleus
* Trochlear nucleus
* GVE
* Edinger–Westphal nucleus

|

Ventral tegmental area|

* Rostromedial tegmental nucleus

* Periaqueductal gray
* Red nucleus
* Rostral interstitial nucleus of medial longitudinal fasciculus
* Parabrachial area
* Interpeduncular nucleus

Midbrain reticular formation|

* Dorsal tegmental nucleus
* Raphe nuclei
* dorsal
* Reticulotegmental nucleus

Base|

| White / Cerebral crus|

* Pyramidal tracts
* Corticospinal tract
* Corticobulbar tract
* Corticopontine tract
* Frontopontine fibers
* Temporopontine fibers

|

Grey / Substantia nigra|

* Pars compacta
* Pars reticulata

Surface|

* Superior cerebellar peduncle
* Decussation
* Interpeduncular fossa

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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)

Authority control databases |

* Terminologia Anatomica

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