The ependymal epithelium is best known for lining the ventricles of the brain. Ependymal cells are clearly defined as a subtype of glial cells because they are nonneuronal cells in the brain that are derived from neuroectoderm. They are made up of ependymocytes, choroid plexus epithelial cells, tanycytes, and Müller cells and retinal pigment epithelial cells.
Ependymal cells form an epithelial layer that lines the brain's ventricles and spinal cord's central canal, respectively. During active brain development, the mammalian ependyma is derived from the ventricular zone, which produces ependymal cells, neuroblasts, and glial cells.
The ependyma is the thin neuroepithelial (simple columnar ciliated epithelium) lining of the brain's ventricular system and the spinal cord's central canal. One of the four types of neuroglia in the central nervous system is the ependyma (CNS). It plays a role in the production of cerebrospinal fluid (CSF) and has been shown to act as a reservoir for neuroregeneration.
The ependyma is made up of glial cells called ependymocytes, which are ependymal cells. These cells line the ventricles of the brain and the spinal cord's central canal, which fill with cerebrospinal fluid. These are nerve tissue cells with a simple columnar shape, similar to mucosal epithelial cells. For their function in circulating cerebrospinal fluid, early monociliated ependymal cells differentiate into multiciliated ependymal cells.
These cells' basal membranes are distinguished by tentacle-like extensions that attach to astrocytes. Cilia and microvilli cover the apical side.
Cerebrospinal Fluid- Ependymal cells, which line the CSF-filled ventricles and spinal canal, play an important role in CSF production and regulation. Their apical surfaces are covered in cilia, which help to circulate CSF around the CNS. Microvilli, which absorb CSF, cover their apical surfaces as well. A population of modified ependymal cells and capillaries known as the tela choroidea form the choroid plexus, which produces CSF, within the ventricles of the brain.
Neuroregeneration- Jonas Frisén and colleagues from the Karolinska Institute in Stockholm demonstrated that ependymal cells act as reservoir cells in the forebrain that can be activated after a stroke, as well as in vivo and in vitro stem cells in the spinal cord. These cells, however, did not self-renew and were depleted as they generated new neurons, failing to meet the requirement for stem cells. According to one study, ependymal cells from the lateral ventricle's lining may be a source of cells that can be transplanted into the cochlea to reverse hearing loss.
The epithelial layer that surrounds the choroid plexus, a network of blood vessels located in the walls of the lateral ventricles, is also formed by ependymal cells (the two largest ventricles, which occur as a pair in the cerebral hemispheres).
What are the ependymal cells functions? They are branched glial cells that nourish neurons while also acting as a barrier between nervous tissue and blood. Ependymal cells blood brain barrier protects against blood-borne infections.
1. What is Ependymoma?
Ans. Ependymomas develop from the ependymal cells that line the spinal cord's ventricles and central canal. These tumours typically form rosettes and appear more epithelial than glial tumours. Ependymomas are less aggressive than astrocytomas and frequently show signs of CSF obstruction. Myxopapillary ependymoma is a rare type of ependymoma that occurs in the distal spinal cord (filum terminale) and has a distinct morphologic appearance as well as an excellent prognosis. Chordomomas (tumours of notochord remnants), which also occur at this site, must be distinguished from myxopapillary ependymomas.
2. What Happens if the Ependymal Cells are Damaged?
Ans. Damaged ependyma may be unable to perform its function in regulating fluid, ion, and small molecule transport between cerebral parenchyma and ventricular fluid, contributing to hydrocephalus.