Ependymalceller

Ependymal cells, known in Swedish as ependymalceller, are glial cells that line the ventricles of the brain and the central canal of the spinal cord. They develop from the neural tube and form the ependymal layer, or ependyma, that covers the luminal surfaces of the ventricular system.

Anatomy and morphology: Ependymal cells are typically cuboidal to columnar in shape. Their apical surface faces the cerebrospinal fluid (CSF) and bears motile cilia, often accompanied by microvilli, which help circulate CSF and increase surface area for exchange. They are joined by tight junctions, contributing to a selective barrier between the CSF and brain interstitial fluid. In certain regions, such as the floor of the third ventricle, specialized variants called tanycytes extend long processes into hypothalamic tissue.

Function: The primary role of ependymal cells is to regulate the composition and movement of CSF within the ventricular system. Ciliary beating promotes CSF flow, while microvilli and transporter proteins participate in solute exchange and homeostasis. In the choroid plexus, a specialized ependymal epithelium contributes to CSF production and regulation.

Clinical relevance: Ependymal cells can give rise to ependymal tumors, known as ependymomas, which commonly occur within the ventricles or spinal canal. These tumors are graded by the WHO system and treated with surgery, and potentially radiotherapy or chemotherapy. Dysfunction or loss of ependymal integrity can contribute to hydrocephalus through impaired CSF circulation.

Development and regeneration: Ependymal cells originate from radial glial lineage and differentiate to form the mature ependymal layer. In adults, they largely maintain barrier and regulatory functions, with limited regenerative capacity.