Genu of corpus callosum

The genu of corpus callosum is the thick, curved anterior part of the corpus callosum. It is continuous posteriorly with the body and inferiorly/posteriorly with the rostrum.

Its commissural fibres curve anteriorly and laterally into the frontal lobes, interconnecting the frontal cortical regions of the two cerebral hemispheres involved in motor and higher cognitive functions. The most prominent anteriorly directed fibres form the forceps minor, which extends into the frontal white matter.

Anatomical relations

Inferiorly, the genu of corpus callosum is closely related to the rostrum. Posteriorly, it provides attachment to the septum pellucidum, which forms the medial wall of the frontal horn of the lateral ventricle. The septum pellucidum extends between the genu and adjacent parts of the corpus callosum superiorly and the anterior columns of the fornix inferiorly. Anteriorly and superiorly, the genu is related to the callosal sulcus and cingulate gyrus.

Important distinction

The genu of corpus callosum is a commissural white-matter structure and should not be confused with the genu of the internal capsule, which contains projection fibres, particularly corticonuclear (corticobulbar) fibres.