Ependymal cells are a specialized type of cells found in the central nervous system and play key functions in the body. These cells line the cerebral ventricles, the central canal of the spinal cord and the central canal of the brain, forming part of what is known as the ependymal epithelium. Throughout this article, we will explore the different types of ependymal cells and the important functions they play in the body.
Types of Ependymal Cells
There are several types of ependymal cells that are classified based on their location and morphology in the central nervous system. Below are the main types of ependymal cells:
Radial Ependymal Cells
Radial ependymal cells are highly specialized cells found in the subventricular zone, where they support adult neurogenesis and neuronal migration. These cells have long, thin processes that extend along the ventricular wall, providing structural support for the generation of new nerve cells.
Tanic Ependymal Cells
Ependymal cells Tannic cells are a subtype of ependymal cells that are characterized by the presence of dark cytoplasmic granules inside. These granules contain various substances, such as lipids and proteins, and are believed to play a role in regulating the microenvironment in which the ependymal cells are found.
Cylindrical Ependymal Cells
The Cylindrical ependymal cells are the most common type of ependymal cells and are characterized by their elongated, ciliated shape. These cells have cilia on their apical surface, which participate in the circulation of cerebrospinal fluid and in the transport of molecules and nutrients along the ependymal pathways.
Functions of Ependymal Cells
Ependymal cells perform multiple functions in the body, which go beyond the simple action of lining the cavities of the central nervous system. Below are some of the main functions of ependymal cells:
Regulation of Cerebrospinal Fluid
One of the key functions of ependymal cells is the regulation of production and circulation of cerebrospinal fluid, which acts as a shock absorber for the brain and spinal cord. The cylindrical ependymal cells, with their cilia, actively participate in the movement of cerebrospinal fluid throughout the cerebral ventricles and the central canal of the spinal cord.
Support for Adult Neurogenesis
Radial ependymal cells play a fundamental role in adult neurogenesis, that is, the generation of new neurons in the adult brain. These cells provide a microenvironment conducive to the proliferation and differentiation of neural stem cells, facilitating the formation of new nerve cells in specific regions of the central nervous system.
Participation in the Blood-Brain Barrier
Ependymal cells contribute to the formation and maintenance of the blood-brain barrier, a highly selective barrier that regulates the passage of molecules and substances from the blood to the brain. These cells act as part of the ependymal epithelium, collaborating in the protection of the central nervous system and in the control of the brain microenvironment.
Response to Brain Injuries
Ependymal cells have the ability to respond to brain injuries and damage to the central nervous system by activating repair and regeneration processes. These cells can proliferate and migrate to the site of injury, contributing to the formation of a glial scar and the restoration of structural integrity in damaged nervous tissue.
Importance of Ependymal Cells
In conclusion, ependymal cells play a fundamental role in maintaining homeostasis of the central nervous system and in regulating various neural functions. Their morphological and functional diversity allows them to participate in processes as varied as the regulation of cerebrospinal fluid, adult neurogenesis and the response to brain injuries. Understanding the importance of ependymal cells is crucial to advancing our knowledge of brain physiology and the treatment of neurological disorders.