Current methods for studying central nervous system myelination
necessitate permissive axonal substrates conducive to myelin wrapping by
oligodendrocytes. We have developed a neuron-free culture system in
which electron-spun nanofibers of varying sizes substitute for axons as a
substrate for oligodendrocyte
myelination, thereby allowing manipulation of the biophysical elements
of axonal-oligodendroglial interactions. To investigate axonal
regulation of myelination, this system effectively uncouples the role of
molecular (inductive) cues from that of biophysical properties of the
axon. We use this method to uncover the causation and sufficiency of
fiber diameter in the initiation of concentric wrapping by rat
oligodendrocytes. We also show that oligodendrocyte
precursor cells display sensitivity to the biophysical properties of
fibre diameter and initiate membrane ensheathment before
differentiation. The use of nanofibre scaffolds will enable screening
for potential therapeutic agents that promote oligodendrocyte differentiation and myelination and will also provide valuable insight into the processes involved in remyelination.
Making myelinating cultures is technically challenging because to have to first make nerves and then get oligodendrocytes to myelinate them. Nerves are cells that do not like to grow and so you end up using feotal cutlures to produce them or use stem cells to grow them. This study shows that you can use fibres to replace nerves and this then allows you to get an assay going to test drugs on ways to test myelination.