The<unk>  (precommissure) is a bundle of white fibers, connecting the two cerebral hemispheres<unk> ross the middle line, and placed in front of the columns of the fornix.
On a sagittal section, it is oval in shape, having a long vertical diameter that measures about 5 mm.
In 1991 brain studies performed by Laura Allen and Roger Gorsky of UCLA noted that the<unk>  was found to be 1/3 larger in men with a homosexual orientation.
Anterior commissure
Arcuate fasciculus
Cerebral peduncle
Anterior limb of internal capsule
Ventral tegmentum
Inferior cerebellar peduncle
Vallecula of cerebellum
Lateral sulcus