Oligodendrocytes (green) wrap electrical insulation called myelin around axons (purple). How an oligodendrocyte determines which axon to myelinate is not clear. This new study shows that electrical impulses stimulate the initial events in formation of myelin. Glutamate released from the axon when they fire impulses stimulates the formation of an adhesive signaling complex between the axon and tips of oligodendrocyte cell processes, which in turn triggers the local synthesis of myelin protein. Through this process, myelin will form preferentially on axons that
are functionally active. This image relates to an article that appeared in the Aug. 4, 2011, issue of Science Express, published by AAAS. The study, by Dr. Hiroaki Wake of the National Institutes of Health, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, in Bethesda, Md., and colleagues was titled, "Control of Local Protein Synthesis and Initial Events in Myelination by Action Potentials."