The brain’s key “breeder” cells secrete substances that boost the numbers and strength of critical brain-based immune cells believed to play a vital role in brain health.
“Transplanting neural stem cells into experimental animals’ brains shows signs of being able to speed recovery from stroke and possibly neurodegenerative disease as well,” said Tony Wyss-Coray, PhD, professor of neurology and neurological sciences in the Stanford School of Medicine. “Why this technique works is far from clear, though, because actually neural stem cells don’t engraft well.”
While of critical importance to maintaining healthy brain function, true neural stem cells are rare. Far more common are their immediate progeny, which are called neural progenitor cells, or NPCs. These robust, rapidly dividing cells are poised to travel down a committed path of differentiation to yield new brain cells of several different types including neurons.
One category of brain cells, microglia, descends not from neural stem cells but from an immune lineage and retains several features of immune cells. “Microglia are the brain’s own resident immune cells,” Wyss-Coray said. Unlike most other mature brain cells, microglia can proliferate throughout adulthood, especially in response to brain injury. They can, moreover, migrate toward injury sites, secrete various “chemical signaling” substances, and gobble up bits of debris, microbial invaders or entire dead or dying neurons.
In a series of experiments, Wyss-Coray and his colleagues have shown that neural progenitor cells secrete substances that activate microglia...
Read more in the Stanford University School of Medicine announcement.