Highly read on www.cell.com/cell-stem-cell in July

Growing evidence suggests that the mammalian brain recruits adult neural stem cells in an attempt to repair diseased or injured neurons. Drugs that can spur on this recruitment are highly sought after.

One candidate is the widely used diabetes drug metformin, which activates an enzyme called aPKC. In the brain, this protein's action on another protein, CBP, is essential for optimal specialization of neural precursor cells.

Freda Miller at the Hospital for Sick Children in Toronto, Canada, and her team showed that metformin also activated the aPKC–CBP pathway in cultured mouse and human neural precursors, promoting neuron generation. Moreover, it enhanced the generation of new neurons in the brains of live adult mice. Crucially, the change seemed to confer a benefit: adult mice treated with metformin showed better spatial-memory formation in a water maze compared with controls.

Cell Stem Cell 11, 23–35 (2012)