An oligodendrocyte is a type of glial cell. Oligodendrocytes maintain and provide myelin to axons. Typically, one oligodendrocyte will support about fifty axons.
Most demyelinating diseases are the result of a malfunction of oligodendrocytes. Although there are several causes of oligodendrocyte dysfunction, the most common is an excess of glutamate. It also appears that oligodendrocytes are involved in several psychiatric disorders, such as schizophrenia.