The isolation of cultured oligodendrocytes from rat optic nerve.

Oligodendrocytes, the myelin-forming cells of the central nervous system, were cultured from newborn rat optic nerve employing a modified method of McCarthy and DeVellis, and cultured oligodendrocytes were analyzed for characteristic morphology and maturation events by phase contrast, MBP immunofluorescent and scanning electron microscopy. Two types of oligodendrocytes, type 1 OLs and type 2 OLs, on poly-L-lysine-coated dishes were obtained. Type 1 OLs showed extensive networks of processes and type 2 OLs elaborated membranous expansion along extensive networks, and it was demonstrated that type 2 OLs developed from type 1 OLs by phase contrast-microscopic observation. By scanning electron-microscopic observation, membrane structure in type 2 OLs clearly corresponded to membranous expansion. Our results suggest that type 1 OLs and type 2 OLs are in the different states of the myelinogenesis, and that membranous expansion and membrane structure in type 2 OLs correspond to myelin membrane.