Researchers at Johns Hopkins Medicine have discovered that oligodendrocyte progenitor cells in the brain are constantly trying to create new myelin-producing cells[1]. Myelin is a protective covering of nerve fibers, which is important for the proper functioning of the nervous system[4]. Research published in the journal Science shows that myelin repair occurs through constitutive differentiation, meaning that this process occurs continuously and not just in response to damage[1][3]. Scientists have observed that when progenitor cells attempt to differentiate, they form dandelion-like structures they call DACS[6]. This discovery changes the current understanding of myelin repair, as previous models assumed that progenitor cells begin to differentiate only in response to changes in neural activity[3]. The findings may have important implications for the development of new therapies to treat diseases associated with myelin damage, such as multiple sclerosis[5].