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Medial surface of left cerebral hemisphere. Uncus is shown in orange.
Human brain inferior-medial view description 3.JPG
Human brain inferior-medial view (Uncus is #5)
Anatomical terms of neuroanatomy

The uncus is an anterior extremity of the parahippocampal gyrus. It is separated from the apex of the temporal lobe by a slight fissure called the incisura temporalis.

Although superficially continuous with the hippocampal gyrus, the uncus forms morphologically a part of the rhinencephalon.

An important landmark that crosses the inferior surface of the uncus is the band of Giacomini.[1]

The term comes from the Latin word uncus, meaning hook, and it was coined by Félix Vicq-d'Azyr (1748–1794).[2]

Clinical significance

The part of the olfactory cortex that is on the temporal lobe covers the area of the uncus, which leads into the two significant clinical aspects of the uncus: uncinate fits and uncal herniations.

The landmark that helps you find the amygdala on a coronal section of the brain.


A sparse amount of literature exists to propose a comprehensive overview of the functionality of the uncus. A study has indicated that psychotic-like experiences were associated with reduced expansion within the uncus between the ages of 14 and 19 in cannabis-using individuals.[3]

Additional images


Public domain This article incorporates text in the public domain from page 826 of the 20th edition of Gray's Anatomy (1918)

  1. ^ Pfleger, René. "Uncus | Radiology Reference Article | Radiopaedia.org". Radiopaedia. Retrieved 17 October 2019.
  2. ^ JC Tamraz, YG Comair. Atlas of Regional Anatomy of the Brain Using MRI (2006), p 8.
  3. ^ Yu, Tao (2020). "Cannabis-associated psychotic-like experiences are mediated by developmental changes in the parahippocampal gyrus". Journal of the American Academy of Child and Adolescent Psychiatry. 59 (5): 642–649. doi:10.1016/j.jaac.2019.05.034. PMID 31326579. S2CID 198135290. Retrieved 15 August 2020.