Stem cell injections might restore memory lost through strokes, Alzheimer’s and other neurodegenerative diseases – at least that’s what experiments in mice suggest.

In previous studies transplanted neural stem cells survived and integrated into brain circuitry, says Mathew Blurton-Jones, a member of the team carrying out the experiments at the University of California at Irvine. “We’ve now gone one stage further in showing that once integrated, these new neurons are able to reverse cognitive deficits associated with neurodegeneration or neuronal loss,” he says.

After the team had destroyed memory cells in the hippocampuses of mice, they performed badly in a standard …