The concept that Schwann and glial cells are related causally to myelin formation evolved slowly, and not without controversy. Perhaps Doinikow1 and del Rio Hortega2 were the chief advocates of the theory that myelin was a product of the activity of Schwann cells in the peripheral nervous system and of oligodendroglia cells within the central nervous system. Debate may still be had when the electron microscopists3,4 attempt to decide which of the glial cells carries the name oligodendrocyte. However, it would not be anticipating our discussion to say that at present there is general agreement with the thesis of Doinikow and del Rio Hortega.3-5
The glial cells again are receiving unexpected interest from contemporary experimentalists.6,7 It has become apparent that there is a spectrum of enzymes and coenzymes present in white matter,8-12 many of which may be located intraglially. Recent studies13 have shown