The hippocampal sulcus is the inferior lateral extension of the transverse fissure (of Bichat), which in turn communicates with the ambient cistern. It is a shallow groove on the medial surface of the hippocampus, between the dentate gyrus and subiculum, inferior to the fimbria and fimbriodentate sulcus 1.
During embryonic development, the hippocampal sulcus appears as a shallow indentation around the 10th week of gestation 1. The hippocampus develops and folds around the hippocampal sulcus between the 13th and 16th weeks of gestation 2. By the 21st week of gestation, all but the most medial/superficial part of the hippocampal sulcus is obliterated due to fusion of the cornus ammonis and dentate gyrus, resembling the adult hippocampal formation 1,2.
- 2. Kier EL, Kim JH, Fulbright RK, Bronen RA. Embryology of the human fetal hippocampus: MR imaging, anatomy, and histology. (1997) AJNR. American journal of neuroradiology. 18 (3): 525-32. Pubmed
- 3. Li Y, Li J, Segal S, Wegiel J, De Santi S, Zhan J, de Leon MJ. Hippocampal cerebrospinal fluid spaces on MR imaging: Relationship to aging and Alzheimer disease. (2006) AJNR. American journal of neuroradiology. 27 (4): 912-8. Pubmed