Glial cells, also known as neuroglia or simply glia, are non-neuronal cells in the central and peripheral nervous system that provide support and protection for neurons. There are several types of glial cells, including astrocytes, oligodendrocytes, microglia, and Schwann cells.

Astrocytes are the most abundant type of glial cell in the brain and play a critical role in maintaining the health and function of neurons. They provide structural support to neurons, regulate the concentration of ions and neurotransmitters in the extracellular space, and contribute to the formation of the blood-brain barrier.

Oligodendrocytes and Schwann cells are responsible for myelinating axons, which increases the speed of nerve impulse transmission. Oligodendrocytes myelinate axons in the central nervous system, while Schwann cells myelinate axons in the peripheral nervous system.

Microglia are the resident immune cells of the central nervous system and play a crucial role in the immune response to injury or infection. They act as phagocytes, removing debris and dead cells from the nervous system, and also contribute to synaptic pruning during development.

In addition to their support and protective functions, glial cells also play a role in neural communication and plasticity. They release neurotransmitters and modulate synaptic transmission, and are involved in the formation and maintenance of synapses.

Overall, glial cells are essential components of the nervous system and play a critical role in maintaining neural health and function.