Commissural fibers of telencephalon

The commissural fibers of commissural fibres of telencephalon (transverse fibers of telencephalon) are white-matter fibres that cross the midline and connect regions of the two cerebral hemispheres, permitting interhemispheric communication and functional integration.. 

The principal commissural fibers of the telencephalon region include:

• Corpus callosum: This is the largest cerebral commissure. It connects widespread cortical regions and is a pathway of crucial importance to speech-language functions. It consists of the rostrum, genu, body, and splenium.

• Anterior commissure: This is a compact commissural bundle crossing the midline near the lamina terminalis. Its fibres principally interconnecIt the olfactory bulbs, amygdaloid nuclei, and the medial and inferior temporal lobes.

• Hippocampal commissure (commissure of fornix): This commissure connects contralateral hippocampi via the crura of the fornix and runs beneath the posterior portion of the corpus callosum.

Collectively, these fibres contribute to the interhemispheric integration of sensory, motor, cognitive and limbic information.

Important distinctions

The commissural fibres be distinguished from association fibres, which connect cortical regions within the same hemisphere, and projection fibres, which connect the cerebral cortex with subcortical structures, brainstem and spinal cord.

Please note that the habenular commissure and posterior commissure also cross the cerebral midline and are considered as the commissural fibres. But these are associated with the diencephalon, and hence not grouped as part of the telencephalon commissureal fibres.