Scientists at the University of California, Santa Barbara have made an important discovery that will increase the understanding of multiple sclerosis, a debilitating disease of the central nervous system in which the myelin sheath, an insulating membrane surrounding the nerve cells in the brain and spinal cord, start to unravel for reasons as yet unknown.
In a paper appearing in the current issue of the Proceedings of the National Academy of Science, several UC Santa Barbara researchers describe the results of a study that shows why the unraveling occurs.
The myelin sheath is made up of a lipid bilayer (similar to those making up the cell membrane) wrapped many times around the nerve axon -- the part of a nerve cell through which impulses travel away from the cell body.
One specific protein, called myelin basic protein, acts to hold the myelin sheath together tightly around the axon. The axons serve as the electrical wires that connect the nerve cells, and the myelin serves as the insulation to keep the electrical impulses flowing quickly and reliably.
"If the myelin breaks down, for whatever reason, the nerve electrical impulses leak out, slow down, and generally don't work very well," says Joe Zasadzinski, professor of chemical engineering at UCSB.