Critical for Coating: Protein directs nerve-sheath construction

Just as plastic coatings insulate electrical wires, myelin sheaths surround nerve fibers in the body. In addition to protecting the fibers, these fatty sheaths speed up the message-carrying impulses and keep extraneous signals from interfering with impulses traveling along the fibers. Although scientists have known about myelin for several centuries, mystery has shrouded the delicate interplay between nerve cells and the glial cells that produce it.