New research findings challenge old beliefs about myelin repair in MS

• New research findings challenge old beliefs about myelin repair in MS

Written by Marisa Wexler, MS | January 28, 2026

• In a new study, researchers report that myelin-making cells are constantly produced in the brain, challenging old beliefs about myelin repair in MS.
• Aging and inflammation, both common in multiple sclerosis, reduce the survival of these new myelin-producing cells.
• These findings could spur the development of new treatment approaches in MS, according to the research team.

Oligodendrocytes, the cells responsible for making myelin, are constantly being made throughout the brain and spinal cord, even when there’s no myelin damage, according to a new study by U.S. researchers.

These findings challenge the long-held view that oligodendrocyte precursor cells mostly differentiate into oligodendrocytes at sites of damage to drive myelin repair. Instead, this differentiation occurs continuously across the nervous system, and local signals determine which newly formed cells survive and make myelin.

The researchers found that inflammation and aging, which are both prominent in multiple sclerosis (MS), reduced the number of newly formed oligodendrocytes that survived. This suggests that future MS therapies may need to focus not only on generating new myelin-producing cells, but also on promoting their survival and ability to function.

“Leveraging this knowledge … may [ultimately] accelerate our understanding [of oligodendrocytes’ role] in MS and spur the development of new approaches … for therapeutic benefit,” the team wrote.

The study, “Myelin is repaired by constitutive differentiation of oligodendrocyte progenitors,” was published in the journal Science. The work was funded by the National Institutes of Health.

Myelin is a fatty substance that wraps around nerve fibers and helps them send electrical signals. In MS, the immune system launches an inflammatory attack that damages myelin, disrupting normal nerve signaling and ultimately leading to disease symptoms.

Researchers focused on myelin processes in brain

Within the brain and spinal cord, myelin is made mainly by specialized cells called oligodendrocytes. While it is well established that mature oligodendrocytes arise from immature cells called oligodendrocyte precursor cells (OPCs), scientists have long thought that this maturation process was largely triggered by myelin damage.

However, scientists have struggled to track the development of mature oligodendrocytes in living brain tissue, which has limited their ability to test how and when these myelin-making cells are actually made.

In the new study, a team led by researchers from Johns Hopkins University in Baltimore identified a structural change that occurs as OPCs mature into oligodendrocytes, allowing them to follow this process more directly.

Specifically, when OPCs differentiate, they remodel the surrounding extracellular matrix, which is the network of proteins outside cells that helps maintain tissue structure. This leads to the formation of a spherical structure that the researchers termed dandelion clock-like structures (DACS) — because, under a microscope, they resemble a dandelion.

By monitoring the appearance of these structures, the researchers were able to track the growth of OPCs into mature oligodendrocytes across the brain and spinal cord in mice. They found that new oligodendrocytes were constantly being made throughout the nervous system — even when there was no damage to myelin.

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