Anterior commissure

The Anterior Commissure (precommissure) is a bundle of white fibers, connecting the two cerebral hemispheres across the middle line, and placed in front of the columns of the fornix.

On sagittal section it is oval in shape, its long diameter being vertical and measuring about 5 mm.

Its fibers can be traced lateralward and backward on either side beneath the corpus striatum into the substance of the temporal lobe.

It serves in this way to connect the two temporal lobes, but it also contains decussating fibers from the olfactory tracts.