Age-related myelin dynamics revealed by increased oligodendrogenesis and short internodes

This study investigates how myelin, a protective sheath around nerve fibers, changes with age in the spinal cord of mice. The researchers found that as mice age, the length of myelin segments (internodes) decreases, suggesting the spinal cord is actively trying to repair myelin. The study also looked at the production of new glial cells, which support nerve cells. They observed an increase in the generation of oligodendrocytes, cells that produce myelin, in the white matter of older mice, further supporting the idea of ongoing myelin repair. Interestingly, the study found that new astrocytes, another type of glial cell, were rarely produced. This suggests that the aging spinal cord prioritizes the production of myelin-producing cells to maintain or repair nerve fiber insulation.

• 1
  Internode lengths of rubrospinal tract axons significantly decrease with age, suggesting active remyelination.
• 2
  Gliogenesis increases in the white matter of the spinal cord in older mice (21 months).
• 3
  Newly generated cells primarily differentiate into oligodendrocytes, with limited differentiation into astrocytes.