The grown‑up brain can heal itself better than scientists once thought. In a study with mice, researchers at the University of Zurich saw special support cells fixing damaged brain parts in a surprising way. Instead of moving whole new cells into the hurt area, the cells sent only brand‑new cell nuclei there.
Support cells called glia keep the brain healthy. One type, astrocytes, looks like tiny stars. Astrocytes feed nerve cells, control blood flow, and help keep brain tissue in good shape.
For a long time, scientists believed that once astrocytes die, an adult brain cannot replace them. This loss happens after injuries or in rare autoimmune diseases such as neuromyelitis optica, where the body attacks its own astrocytes.
Astrocytes Rebuild Lost Tissue
When brain tissue is damaged, astrocytes gather around the edges and start rebuilding the lost network. "Our results show that adult brains have a hidden repair ability," says lead researcher Dr. Weber. "This could lead to new ways to help people recover from diseases that destroy astrocytes."
New Nuclei Travel to the Injury
To watch the repair, the team used two‑photon microscopy to look at live mouse brains for several weeks. They also measured which genes turned on in different brain zones. These tools let them spot the exact astrocytes that repaired the tissue.
Instead of just dividing, the repairing astrocytes do something unusual: the new nuclei made by their daughter cells move long distances inside the astrocyte’s long branches, heading straight for the damaged spot. "They glide their fresh nuclei across the brain, knitting the astrocyte network back together," explains Weber.
New Paths for Brain Healing
Finding that nuclei can travel through adult astrocytes adds a fresh layer to our understanding of brain self‑repair. If scientists can learn how to switch on this process on purpose, they might help rebuild brain tissue, restore astrocyte networks, and speed up recovery from certain brain disorders.
The researchers also listed many genes and signaling pathways that light up only while repair is happening. These biological clues could become targets for future treatments that boost regeneration after injury or disease.
"We identified dozens of temporary genes and pathways that act during repair," says Weber. "They could be the starting points for future drugs that guide the brain to heal itself."