Rat Cortical Oligodendrocyte–Embryonic Motoneuron Co-Culture: An <I>In Vitro</I> Axon-Oligodendrocyte Interaction Model

Mechanisms that control the differentiation and function of oligodendrocytes in the central nervous system are complex and involve multiple inputs from the surrounding environment, including localized concentrations of growth factors and the extracellular matrix. Dissection and analysis of these inputs are key to understanding the pathology of central nervous system demyelinating diseases such as multiple sclerosis, where the differentiation of myelinating oligodendrocytes from their precursors underlies the remission phase of the disease. In vitro co-culture models provide a mechanism for the study of factors that regulate differentiation of oligodendrocyte precursors but have been difficult to develop due to the complex nature of central nervous system myelination. This study describes development of an in vitro model that merges a defined medium with a chemically modified substrate to study aspects of myelination in the central nervous system. We demonstrate that oligodendrocyte precursors co-cultured with rat embryonic motoneurons on non-biological substrate (diethylenetriamine trimethoxy-silylpropyldiethylenetriamine), can be induced to differentiate into mature oligodendrocytes that express myelin basic protein, using a serum-free medium. This defined and reproducible model of in vitro myelination could be a valuable tool for the development of treatments for demyelinating diseases such as multiple sclerosis.