Scientists have discovered that Schwann cells are much more prolific in generating a protective sheath covering nerve fibers than previously believed. The revelation raises the possibility of new avenues to treat nerve injuries and various forms of neuropathy. Further research could prove useful in promoting myelin repair in central nervous system disorders such as multiple sclerosis, where damage to myelin slows or blocks electric signals from the brain.

Two types of cells in the body produce myelin: oligodendrocytes in the brain and spinal cord, and Schwann cells in the rest of the body. Until now, scientists thought that only oligodendrocytes generated multiple myelin sheaths around axons, the slender projection of a nerve cell that carries electrical signals between cells. The new research reveals that Schwann cells also are capable of spreading myelin across multiple axons.

Researchers at Oregon Health and Science University made the discovery after conducting a genetic screen in zebrafish in the laboratory. They discovered some fish had more myelin than expected, and those fish carried a mutation in a gene called fbxw7. When they knocked out the gene in genetically modified mice, they discovered an unexpected characteristic: individual Schwann cells began spreading myelin across many axons.

In discovering how Schwann cells generate myelin at the molecular level, the discovery may lead to new gene-therapy techniques to repair damaged myelin. Results of animal model studies sometimes do not translate to humans and may be years away from being a marketable treatment. However, the study’s author said targeting the fbxw7 gene – or downstream pathway molecules – could be a powerful way to promote myelin repair in the central nervous system.

The findings were published in the journal Nature Communications.