Tamara Bhandari writing for Washington University School of Medicine, St. Louis reports that Neurons in the brain and spinal cord don’t grow back after injury, unlike those in the rest of the body. Cut your finger, and you’ll probably be back to using it in days or weeks; slice through your spinal cord, and you likely will never walk again. Now, working in mice, researchers at Washington University School of Medicine in St. Louis have identified some of the key steps taken by peripheral nerves – those in the arms and legs – as they regenerate. The findings, published the week of Dec. 10 in Proceedings of the National Academy of Sciences, lay out a path that neurons of the spinal cord might be able to follow – potentially leading to improved recovery for people paralyzed by spinal cord injuries. “We’ve figured out some of the events that are required for injured peripheral nerves to repair themselves, and we can see that these things fail to happen in the central nervous system,” said Valeria Cavalli, PhD, an associate professor of neuroscience. “So now we’re trying to see if turning on these networks can help spinal cord neurons regenerate.” About 11,000 people in the United States survive a spinal cord injury every year. Such injuries most often are caused by car and motorcycle accidents, falls, contact sports and diving, or gunshots. Paramedics can reduce the risk of further damage by quickly and gently immobilizing the spine, but there’s no way to reverse a spinal cord injury that has already occurred. The neurons that form the spinal cord do not spontaneously heal themselves.