Oligodendrocytes (from
Greek, meaning
cells with a few branches), or
oligodendroglia (Greek,
few tree glue), are a type of
neuroglia. Their main functions are to provide support and insulation to
axons in the
central nervous system of some
vertebrates, equivalent to the function performed by
Schwann cells in the
peripheral nervous system. Oligodendrocytes do this by creating the
myelin sheath, which is 80% lipid and 20% protein. A single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 µm of myelin sheath around each axon; Schwann cells, on the other hand, can wrap around only one axon. Each oligodendrocyte forms one segment of myelin for several adjacent axons.