Abnormal myelin maturation in vitro: the role of cerebrosides

Myelinating neonatal rat cerebellar explants were maintained for up to 130 days in vitro. Myelin fractions were extracted from explants of different ages and purified by density gradient centrifugation. Three fractions obtained were termed "light myelin", "heavy myelin" and "membrane fraction" and were deficient in glycolipids compared to myelin fractions prepared from 15-day-old rat cerebellum. The culture myelin has an apparently normal ultrastructure but may not be as stable as myelin with a normal glycolipid composition.