Ependymal cell 2026-11-05
An ependymal cell is a cell of the ependyma, the lining of the brain ventricular system and central canal of the spinal cord. Many ventricular ependymal cells carry multiple motile cilia facing the cerebrospinal fluid. Their coordinated beating can move nearby fluid; the cells are distinct from the neurons whose signaling circuits surround the cavity.[ref]
In a 2016 study, organized cilia modules in the mouse third ventricle generated structured fluid-flow networks and a periodically switching flow pattern.[ref] The result illustrates how an epithelial lining can actively organize its fluid environment rather than simply delimit it. A cilium on one cell acts locally; tissue-level organization determines the collective transport pattern.
Tanycytes are specialized ependymal-related cells with long processes. Their geometry and functions should not be assigned indiscriminately to every ependymal cell.
Tanycyte 2026-11-05
A tanycyte is a specialized ependymal cell and glial cell of the hypothalamus. Its body can line the third ventricle, while a long process extends toward underlying tissue. In the median eminence, tanycytic endings surround neurosecretory terminals near blood vessels.[ref]
This supplies an illuminating example of structural regulation: a glial cell can change the geometry around a neuron's ending without changing the ending's identity. Evidence for one such interaction does not establish identical functions for every tanycyte subtype.