The identification of a new marker is making it possible to track brain stem cells for the first time, U.S. researchers report. The achievement is already opening doors to new research into depression, early childhood development and multiple sclerosis, the team's senior author said. "This is a way to detect these cells in the brain, so that you can track them in certain conditions where we suspect that these cells play a certain role," explained Dr. Mirjana Maletic-Savatic, an assistant professor of neurology at the State University of New York, Stony Brook. "This is also very applicable for situations where...