This research project will focus on the mechanism and factors responsible for the development of autoimmune demyelination in the central nervous system. Central nervous system myelin is a sheath that covers the axon and together (myelin and axon) are functionally responsible for transmitting signals from the brain to other parts of the body. Any disturbance in the association between myelin and axons, such as myelin loss (demyelination), will have grave effects on brain function. Demyelination is an immunological process that involves the body's defenses, particularly the white cells (known as lymphocytes); once activated, the white cells enter the brain and begin the process of demyelination. Recent studies using a rat animal model have shown that the process of white cell activation involves a particular antibody, a unique protein produced by another type of white cells. The aim of this study is to prepare large amounts of this antibody with highly restricted specificity, known as monoclonal antibody, and document the molecular properties. A second monoclonal antibody against the first antibody will be prepared, using both monoclonal antibodies to study synergistic and/or antagonistic roles in the activation of white cells. A clear understanding of the mechanism responsible for activating and controlling the processes by which a particular white cell destroys normal myelin of the central nervous system is anticipated, utilizing the unique experimental system in this study.