Old stem cell barriers fade away

In young brains, damaged proteins confined in newly formed neurons

THE GREAT DIVIDE  Young brain stem cells (one shown dividing, left) pack old proteins tagged with ubiquitin (red) into one daughter cell. Old cells (one shown dividing, right) lose a barrier that segregates the damaged proteins. DNA is shown in gray.

D. Moore et al/Science 2015

Breaking down barriers usually sounds like a good thing, but not for aging stem cells.