Corticopontine fibers

Brain: 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.
Latin	fibrae corticopontinae, tractus corticopontinus
Gray's	subject #191 862
NeuroNames	ancil-375

Corticopontine fibers are projections from the cerebral cortex to the pontine nuclei.

Depending upon the lobe of origin, they can be classified as frontopontine fibers, parietopontine fibers, temporopontine fibers and occipitopontine fibers.

They are motor fibers that stretch from the precentral gyrus (motor strip) to the nuclei of cranial nerves V (trigeminal), VII (facial) and XII (hypoglossal). These fibers run alongside the corticospinal fibers.

Clinical significance

Several clinical phenomena result from injury to the corticopontine fibers. The corticopontine fibers to cranial nerves V and XII descend to bilateral nuclei. Injury to these fibers result in tongue weakness (cranial nerve XII) and jaw weakness (cranial nerve V) but not full paralysis. The corticopontine fibers to cranial nerve VII descend to innervate bilateral sub-nuclei that supply the forehead but only contralateral to the sub-nuclei that supply the lower face. Injury to these fibers results in paralysis of the lower face, but only weakness of the forehead.

External links

• Brainstem at UWisc 16Pontine