Glial cells are cells in the nervous system that exist alongside neurons. For every neuron, about 10 glial cells exist. It is believed that there are approximately 86 billion neurons in the human brain. This therefore amounts to about 860 billion glial cells. These cells are specialized to take care of the neurons. Of course, it sounds a little crazy that neurons need care, but glial cells help with the following functions, among others:
Of course, these functions are not all performed by the same type of glial cell. So, there are a lot of types of glial cells, all of which have different specializations.
Astrocytes are responsible for the chemical environment of the neurons. To keep the environment stable and safe, the astrocytes remove ions, and recycle neurotransmitters released from processes at the synapse. As far as is now known, astrocytes are the building blocks of the blood-brain barrier, and thus ensure that not all substances from the blood can move into the fluids of the brain.
Oligodendrocytes are responsible for creating myelin in the central nervous system. That this is very important for the proper functioning of the brain is already clear, but recent research has even shown a link between intelligence and the amount of myelin in the brain. The more myelin, the higher the IQ!
Ependymocytes form a membrane around the system of ventricles. The ventricles contain cerebrospinal fluid that is produced by the ependymocytes. In addition, ependymocytes keep the cerebrospinal fluid circulating through the nervous system.
Radial glia cells have an important role during brain development. This is because these cells form a web in the not yet formed brain, through which neurons can migrate to reach their place in the telencephalon.
Author: Myrthe Princen (translated by Melanie Smekal)