Index
Ependymocytes are cells that make up the ependyma, the membrane that lines the inside of the ventricular cavities of the central nervous system.
Classification
There are four myocytes in the central nervous system and two types of myocytes in the peripheral nervous system.
In short, the glyocytes of the central nervous system form neuroglia, which means “nerve glue.”
Their number is much higher (9 times) than that of neurons in the central nervous system, thus constituting half of the total mass of the brain (part of the nervous system located in the skull).
Neuroglia consists of:
Astrocytes
Astrocytes are the cells that belong to the macroglia. They come in star-shaped cells and provide nutrition protection support functions.
These cells are provided with numerous radiating extensions that attach to capillaries (tiny vessels) and neurons. Finally, astrocytes allow neurons to heal in case of injury and appear to communicate with each other.
Oligodendrocytes
Oligodendrocytes mean cells with little (oligos).
Small oligodendrocytes are aligned along the axons corresponding to the central portion of the cylindrical end of the neuron’s body, allowing the transmission of nerve impulses, particularly around the thick axons of the central nervous system and their cytoplasmic extensions.
They wrap around them, forming an insulating envelope: the myelin sheath. Myelin is the lipid (fat) substance that surrounds and protects axons.
Physiology
These cells are lined up inside the cavities that contain the cerebrospinal fluid, a fluid that circulates in all the holes of the central nervous system; these cavities are about each other.
The ependyma is the canal located in the middle of the spinal cord, which carries cerebrospinal fluid from the cerebral ventricles.
Ependymoma is a permeable barrier between the cerebrospinal fluid and the fluid, interstitial fluid in which the central nervous system cells are immersed.
Thanks to the beating of your eyelashes, these cells ensure the circulation of cerebrospinal fluid, also called cerebrospinal fluid.
Ependymodies provide a protective cushion for the brain and spinal cord.
For specialists in cell biology, primary cells are attached using apical junctions: zonula adhaerens, more particularly, gap junctions. It is a layer of cells that is not entirely waterproof except for the choroid plexus.
There is the presence of other structures called aquaporins. This is a variety of channels that carry water.
Ependymal cells are vital in the reabsorption secretion between the brain parenchyma (functional brain tissue) and the cerebrospinal fluid, called cerebrospinal sap.
Therefore, it is a set of structures that constitute a protective barrier and an interface between two complementary histological systems.
The neuroglia is the tissue (set of cells) that supports the nervous system. It serves, among others, the protection of neurons (nerve cell bodies).
The nervous tissue, the set of all the cells that make up the nervous substance, looks pretty complex. It is not; this tissue is made up of two main types of cells, which are:
- Neurons, nerve cells themselves, can excite, produce and transmit electrical signals.
- Gliocytes, called glial cells, are smaller, enveloping and protecting neurons.
All neurons are associated with myocytes. They do not have the property of excitability and therefore cannot transmit nerve impulses like neurons.
Repair of the cerebral ventricles
Ependymal cells can close lesions caused by mechanical lesions in the wall of the cerebral ventricles.
This observation by researchers from the Department of Medicine at the University of Freiburg offers a better understanding of the origin of certain brain diseases such as edema and hydrocephalus.
The eponymous to fight against brain injuries and diseases: Department of Medicine, Dr. Viktoria Szabolcsi Prof. Marco Celio’s research group has shown that in the brain of mice, ependymal cells are capable, thanks to their mobility, of healing mechanical injuries of the cerebral ventricles.
These cells are a particular form of epithelial tissue that covers the brain’s ventricles, the cavities of the brain that contain cerebrospinal fluid. They are composed of a single layer and equipped with movable tabs; they are highly specialized and can hardly be regenerated.
They form an essential barrier between the cerebrospinal fluid and the brain. As they can’t multiply, their disappearance leads to irreversible scars, cerebral edema, or even ventricular enlargement (hydrocephalus).
Although ependymal cells have received increasing attention in the last twenty years, their exact role in brain damage is still largely unknown.
Healing through movement
In the mouse brain, mechanical damage to ependymal cells was found to cause overexpression of parvalbumin. This calcium-binding protein is also expressed in specific nerve cells and fast-twitch muscles.
Parvalbumin overexpression increases ependymal cells’ mobility, allowing rapid recovery from injury.
In mice lacking parvalbumin, this re-epithelialization process is inhibited, underscoring the role played by this protein in cell motility.
When the healing of a lesion of the ependymal layer, based on the proliferation of ependymal cells, is not possible, increasing their motility is an alternative for repairing said damage.
The results will serve as the basis for future research on the influence of parvalbumin on cerebral edema and hydrocephalus. Furthermore, this protein could also be used as a potential marker in diagnosing diseases related to the ependyma.
