Oligodendroglia can be isolated in bulk from fresh lamb or bovine brain white matter and can now be maintained in culture for several days. The cells remain intact and viable and are capable of synthesizing both lipids and proteins, in vitro. While in culture the cells elaborate whorls of membrane which have many features in common with myelin. Thus a model system to study the properties of oligodendroglia has been established. With it our research will concentrate on a) the surface topography of the purified cells and, b) glial myelin membrane assembly. For study of the cell surface components, methods will involve the use of surface labeling probes, radioiodinated lectin binding, and immunoprecipitation with specific antiserum samples. To determine how this glial myelin is assembled, the synthesis of specific lipids or proteins for insertion into this membrane at different time points will be assessed. The findings obtained from these projects will then be applied to the study of human demyelinating diseases, especially Multiple Sclerosis.