Neurons are the primary functional units of the nervous system, while astrocytes, oligodendrocytes, and microglia are all types of glial cells.

Astrocytes play a crucial role in maintaining the chemical balance of the extracellular environment around neurons, regulating ion concentrations, and removing neurotransmitters.

Oligodendrocytes are responsible for producing myelin sheaths around axons in the central nervous system, which insulates the axons and increases the speed of nerve impulses.

Microglia are the resident macrophages of the central nervous system and play a crucial role in immune surveillance and response, phagocytizing cellular debris, pathogens, and damaged neurons.

Schwann cells are responsible for producing myelin sheaths around axons in the peripheral nervous system, which insulates the axons and increases the speed of nerve impulses.

Radial glial cells are neural stem cells that play a crucial role in the development of the central nervous system, generating new neurons and glial cells through a process called neurogenesis and gliogenesis.

Astrocytes play a crucial role in the formation and maintenance of the blood-brain barrier, a specialized network of blood vessels that regulates the entry of substances from the bloodstream into the central nervous system.

Satellite glial cells, also known as amphicytes, are found in the peripheral nervous system and play a role in modulating synaptic transmission, regulating the release and uptake of neurotransmitters at synapses.

Microglia are involved in the clearance of amyloid-beta plaques, a hallmark of Alzheimer's disease, through phagocytosis and the release of inflammatory mediators.

Ependymal cells line the ventricles of the brain and the central canal of the spinal cord, forming a protective barrier and regulating the flow of cerebrospinal fluid.

Both astrocytes and oligodendrocytes have been implicated in the regulation of sleep-wake cycles, with astrocytes playing a role in sleep promotion and oligodendrocytes involved in sleep-wake transitions.

NG2 glia, also known as polydendrocytes, are a type of glial cell that can differentiate into new neurons and glial cells, contributing to neural plasticity and repair.

Müller cells, a type of glial cell found in the retina, play a crucial role in the formation of the optic nerve by guiding the axons of retinal ganglion cells towards the optic disc.

Schwann cells are responsible for producing myelin sheaths around axons in the peripheral nervous system, which insulates the axons and increases the speed of nerve impulses.

Pericytes, a type of glial cell associated with blood vessels in the brain, play a role in regulating blood flow and maintaining the integrity of the blood-brain barrier.