A mechanism for the segregation of age in mammalian neural stem cells

Youthful damage limitation in stem cells Every day brings more risk of damage to stem cells, which could have consequences for the whole organism. Moore et al. observed that dividing neural stem cells in rodents establish a diffusion barrier that restricts damaged proteins to one daughter cell, leaving the other with intact molecules. But with age this diffusion barrier weakens, so that replicating stem cells of older animals are less able to exclude damaged proteins than are the stem cells of younger rodents. Science , this issue p. 1334