A neuron transplant has rewired damaged brain areas in mice, raising hopes that similar transplants might one day help to treat spinal-cord injuries, Parkinson’s disease and other brain conditions. Jeffrey Macklis at Harvard University and his colleagues took healthy neurons from mouse embryos that had been labelled with a green fluorescent protein. They used them to repair a brain circuit involved in the regulation of food intake and body weight in response to a hormone called leptin in mutant mice born with damage to that area, which become dangerously overweight as a result.
