Notch signalling regulates stem cell numbers in vitro and in vivo

One barrier to using stem cells for therapies is the difficulty in controlling their growth and differentiation. Androutsellis-Theotokis et al. show that the Notch receptor plays a pivotal role in a pathway that controls the survival of embryonic, fetal and adult stem cells, and that administration of Notch ligands to the brains of adult rats can help the animals recover movement after a simulated stroke. The finding paves the way towards therapies that aim to encourage the body's endogenous stem cells to repair damage, rather than trying to grow and transplant new cells.