Corticopontine fibers

Corticopontine fibres are descending projection fibres that arise widely from the cerebral cortex and terminate in the ipsilateral pontine nuclei. They form the first part of the corticoponto-cerebellar pathway, through which the cerebral cortex influences the planning and coordination of movement.

They are commonly grouped into frontopontine fibres, arising mainly from the frontal cortex, and parieto-occipito-temporopontine fibres, arising from the parietal, occipital and temporal cortices. The fibres descend through the corona radiata and internal capsule, then pass through the cerebral peduncle to reach the pontine nuclei.

Neurons of the pontine nuclei subsequently give rise to transverse pontocerebellar fibres, which cross the midline and enter the contralateral cerebellar hemisphere, mainly through the middle cerebellar peduncle. Thus, corticopontine fibres themselves do not cross the midline or directly terminate in the cerebellum.