A stress hormone may help the brain repair itself

Date: August 14, 2026 Source: Max Planck Institute of Psychiatry Summary: A surprising stress-related signal may help the brain repair itself after injury. Researchers found that myelin-producing precursor cells rapidly release the stress hormone CRH near damaged brain tissue, helping control how those cells mature and rebuild protective nerve insulation. The same system also influences brain development and the thickness of myelin later in life. The findings could offer new clues about how early-life stress contributes to psychiatric disorders. Share: Facebook Twitter Pinterest LinkedIN Email FULL STORY Maturation of CRH-producing oligodendrocyte progenitor cells after brain injury: CRH expression in OPCs can be triggered . The cells in the middle are highly branched pre-myelinating oligodendrocytes, while the cell on the left has already matured into a myelinating oligodendrocyte. Psychiatry When laboratory mice experience brain damage, e. g., from an injection, Jan Deussing repeatedly notices the same response. A particular group of cells appears and becomes active around the damaged area. Although Deussing, a research group leader and experienced neurobiologist, had observed the phenomenon many times, he did not know exactly what type of cells were involved. The mystery became an ideal research question for a master's student. Clemens Ries, who had recently joined the Max Planck Institute of Psychiatry for an internship as he approached the end of his biology degree, took on the challenge. Identifying the Brain's Repair Cells Using a mouse model, Ries systematically tested markers for all known cell types. Only one produced a response: the marker for oligodendrocyte progenitor cells (OPCs). These precursor cells can mature into oligodendrocytes, which produce the myelin sheath surrounding axons. Axons are extensions of nerve cells that allow neurons to communicate with one another. Myelin acts much like the insulating material around an electrical cable. It supports efficient information transmission along axons and also helps supply them with nutrients, making it vital to healthy brain function. Damage to myelin can have serious consequences. In autoimmune diseases such as multiple sclerosis (MS), the protective coating breaks down. Physical injuries can also harm myelin, and in severe cases, the resulting damage can lead to the death of entire neurons. Restoring myelin around affected axons is therefore an important part of the brain's response to injury. A Surprising Stress Hormone Appears After Injury Ries initially studied the newly identified cells for his master's thesis. "The topic remained so exciting that it became my doctoral thesis," says the biologist.