hree cross-section images of nerve tissue from cats, each showing an individual oligodendrocyte cell (marked with “O”) among nerve cell axons surrounded by dark-colored sheaths of myelin.

Myelin is a fatty substance that surrounds and insulates nerve fibers in the brain and spinal cord, forming a sheath that facilitates the rapid transmission of electrical signals between neurons.

The drug, LL-341070, enhances the brain's ability to repair damaged myelin— the protective sheath around nerve fibers. Damage to myelin is a hallmark of diseases like MS, as well as a natural ...