Anterior commissure

Last edited and medically reviewed by Alaric Steinmetz on 31.12.2023

Synonyms: AC, Anterior commissure

The anterior commissure is one of the fiber systems that connects the two cerebral hemispheres.

Anatomy

The anterior commissure crosses immediately anterior to the Columnae fornicis, superior to the Lamina terminalis of the Hypothalamus, where it divides into two fiber bundles. A thin anterior part courses with its fibers to the Substantia perforata anterior and connects with the olfactory tract. The posterior, more fiber-rich part radiates into the anterior portion of the Temporal lobe.

Figure

Anterior commissure, Sobotta — Anterior commissure in an anatomical drawing from Sobotta, Figure 648.

Third ventricle, sagittal view — Sagittal section through the third ventricle. Figure adapted from Albert Rhoton 2002 in Neurosurgery.

Endoscopic view of the third ventricle — Endoscopic view into the third ventricle through a supracerebellar infratentorial approach, showing the interthalamic adhesion, fornix, and anterior commissure. Figure adapted from Rhomberg T and Henry WSS. Microsurgical Resection of a Pineal Cyst via a Paramedian Supracerebellar Infratentorial Approach. World Neurosurgery 185 (2024): 113. DOI 10.1016/j.wneu.2024.02.049

Imaging

Anterior commissure on MRI — Visualization of the anterior commissure (red arrow) on a sagittal T2 MRI image.

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