During the process of myelination in vertebrates axons are spirally ensheathed by the oligodendroglial plasma membrane. This ensheathment consists of a highly specialized membrane with a distinct protein and especially lipid composition. Unlike other biological membranes the myelin membrane is highly enriched in galactosylceramide and cholesterol. In this study we used a neuron-glia co-culture system to analyze changes of the oligodendroglial membrane structure after contact with neurons and during myelination. Besides biochemical methods, several microscopy techniques such as stimulated emission depletion and fluorescence resonance energy transfer microscopy were applied to evaluate membrane organization on a nanoscale resolution. We were able to show a myelin basic protein dependent reorganization of the oligodendroglial membrane with a neuronal-dependent clustering of galactosylceramide in oligodendrocytes.
