"Profiling of human brains across lifespan shows that the frequency of NSCs declined exponentially across the first two decades of life, but stabilized thereafter, still present in the brains of donors as old as 90 years."
Pedro Pimentel-Coelho
Isolation of postnatal human neural stem cells https://www.biorxiv.org/content/10.64898/2026.06.11.731596v1