Scientists have improved upon their own previous world-best efforts to pluck out just the right stem cells to address the brain problem at the core of multiple sclerosis and a large number of rare, fatal children’s diseases. Details of how scientists isolated and directed stem cells from the human brain to become oligodendrocytes -- the type of brain cell that makes myelin, a crucial fatty material that coats neurons and allows them to signal effectively -- were published online and in the October issue of Nature Biotechnology by scientists at the University of Rochester Medical Center and the University at Buffalo.