Modafinil is a wakefulness-promoting agent approved to improve wakefulness in adults who experience excessive sleepiness due to obstructive sleep apnea or shift work sleep disorder. It is used off-label in MS to treat fatigue and sleepiness.
Myelin is a fatty white substance that surrounds the axon dielectric (electrically insulating) material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system.It is an outgrowth of a type of glial cell.The production of the myelin sheath is called myelination. In humans, myelination begins in the 14th week of fetal development, although little myelin exists in the brain at the time of birth.t is essential for the proper functioning of the nervous system. It is an outgrowth of a type of glial cell. The production of the myelin sheath is called myelination. In humans, myelination begins in the 14th week of fetal development, although little myelin exists in the brain at the time of birth.
myelin. the lipid substance forming a sheath (the myelin sheath) around the axons of certain nerve fibers; it is an electrical insulator that serves to speed the conduction of nerve impulses in these nerve fibers, which are called myelinated or medullated fibers. adj., adj myelinÂ´ic.yelinated nerve fibers occur predominantly in the cranial and spinal nerves and compose the white matter of the brain and spinal cord. It is the myelin sheath that gives the whitish color to the areas of white matter.