Myelin, which insulates axons in the central nervous system is produced by oligodendrocytes. But not all oligodendrocytes are equal.Led by Dr. Jonathan Vinet of the University Laval in Quebec, scientists have identified three different types of oligodendrocytes in the mouse hippocampus: “ramified,” “stellar,” and “smooth.”
http://www.msrc.co.uk/index.cfm/fuseact ... ageid/1104