Comparison of oligodendrocytes grown in neocortex and spinal cord aggregate cultures.

Mechanically dissociated cells of mouse central nervous system (CNS) (neocortex and spinal cord) form spherical aggregates in rotation culture and develop into populations of mature neurons and glial cells. Synapses and myelination of axons are evident in these aggregates although onset of these processes differs between aggregate types. In this study neocortex aggregates display synapses at 2 weeks in culture but do not demonstrate myelination of axons until 8 weeks. Spinal cord aggregates demonstrate myelinated axons at 2 weeks in culture although there are few synapses evident. The difference in myelination onset is due in part to the development of predominantly perineuronal oligodendrocytes in neocortex aggregates compared to the development of interfascicular oligodendrocytes in spinal cord aggregates. Both types of oligodendrocytes exhibit light, medium and dark categories and both cell types are capable of myelinating axons in culture.