Our nerve endings (axons) rely on a protective outer layer called myelin to insulate their lively signals, a bit like the plastic coating on electrical wires. The little round blobs pictured are microscopic myelin makers, known as oligodendrocytes, migrating towards tiny conical mounds of silicon, each 1000-times smaller than a sand castle. Each mound, or ‘micropillar’, acts like an exposed axon, prompting the oligodendrocytes to transform into stringy myelin-forming cells (top left), which coil protectively around the silicon cones. This is actually a chemical test site – drugs can be flooded in around the micropillars to discover those which encourage myelin growth, their effects measured from above by counting the rings of myelin wrapped around the cones. Finding chemicals which boost myelin growth could help to reverse degenerative nervous diseases like multiple sclerosis, were myelin is worn away leaving nerves fragile and exposed.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.