What are the types of glial cells?
Glial cells are different from neurons: as the picture above shows, the neurons are shown in yellow, and the glial cells are red and blue (albeit they are not coloured like this in real life). There are two main different types of glial cells that exist within the nervous system: astrocytes and oligodendrocytes. They are considered as partners to neurons and are often involved within brain pathology, because these cells are responsible for regulating the release of neurotransmitters under normal circumstances. In this page, I’ll discuss both the main types of glial cells as well as ependymal cells, because this also plays a vital brain function.
What are the functions of glial cells as opposed to neurons?
Glial cells perform several functions within the brain in conjunction with neurons:
- Acting as a physical support for neurons
- Supply of nutrition and essential oxygen for the neurons
- Acting as an insulator between different neurons via a myelin sheath
- Remover of dead neurons
- Destroyers of pathogens
- Formation of myelin for the neurons
- Clearance of neurotransmitters from the synaptic clefts
- Repair of neurons after brain injury
Astrocytes, as the picture alongside shows, are star-shaped cells. You may think that neurons are the majority of cells within the nervous system because they conduct electrical charge: but that is not true, in actual fact, astrocytes are the most common types of cells located there.
As well as serving the functions mentioned above, there is another main thing that astrocytes are mainly responsible for within the central nervous system: providing vital nutrition to the brain in times of times of food shortage by the break down of glycogen contained with their cells. Unlike other cells within the body, the brain is only capable of using glucose, so if these cells weren’t there, the brain would shut down fairly soon after the glucose and glycogen stores in your body run out.
Oligodendrocytes help provide the brain with structural integrity via their processes attaching themselves to the axons of nearby neurons. They are also responsible for creating the myelin sheath around the neurons.