The
subcommissural organ (SCO) is one of the
circumventricular organs. It is a small glandular structure formed by
ependymal cells and hypendymal cells and is located in the dorsocaudal region of the
third ventricle, at the entrance of the
cerebral aqueduct. The SCO is one of the first differentiated brain structures to develop. It has its name because of the localization in the
brain. The organ's main functions are unknown; nevertheless, some evidences suggest that the organ may participate in different process, such as the clearance of certain compounds and the circulation of the
cerebrospinal fluid, and it could also play a role in some morphogenetic mechanisms.