Scientists have found how the brain decides the length of the protective coating around nerve fibres. A protein called Piezo1 acts as the measuring tool.

Researchers at Upstate Medical University discovered that oligodendrocytes, the cells that make myelin, use Piezo1 to sense the diameter of the nerve fibres they wrap. That measurement sets each myelin segment’s length.

Piezo1 is a mechanosensitive ion channel. As the cell membrane wraps a wider fibre, the tension activates Piezo1, signalling the cell to extend the coating proportionally. It matters most in the early stages of myelin formation.

Myelin is the fatty insulation around nerve fibres. It controls the speed and efficiency of nerve signals. Precise myelin patterns are essential for healthy brain wiring.

The team was led by Marie Bechler, with Amanda R. Young as first author. The study appeared in PLOS Biology on September 21.

Understanding this mechanism could guide future research into disorders that damage myelin.