Glia Cells

Neurons constitute only about half of the volume of the central nervous system. The rest consists of a variety of supporting cells, the most important of which is neuroglia or ‘nerve glue’. In a very real sense, glia cells (as they are usually called) glue the CNS (central nervous system) together. Besides, they also perform the following functions:

1. These cells surround the neurons and hold them together
2. They supply the neurons with various chemicals, including some that they need in order to exchange messages with other neurons
3. They insulate neurons from one another so that the neural messages do not get scrambled
4. They regulate the chemical composition of the extra-cellular fluid
5. The glia cells also act as house keepers, destroying and removing the dead neurons that are killed by injury or that die as a result of old age.

There are several types of glia cells, some of the most common being astroglia and microglia.