Neurons grown in petri dishes from stem cells have successfully been transplanted into animals’ brains and could one day benefit sufferers of spinal cord injuries. “Healthy brains have stable and precise connections between cells that are necessary for normal behavior. This new finding is the first to show that stem cells can be directed not only to become specific brain cells, but to link correctly. In this study, a team of neuroscientists led by James Weimann, PhD, of Stanford Medical School focused on cells that transmit information from the brain's cortex, some of which are responsible for muscle control. It is these neurons that are lost or damaged in spinal cord injuries and amyotrophic lateral sclerosis (ALS). ‘These stem cell-derived neurons can grow nerve fibers between the brain's cerebral cortex and the spinal cord, so this study confirms the use of stem cells for therapeutic goals,’ Weimann said. To integrate new cells into a brain successfully, the researchers first had to condition unspecialized cells to become specific cells in the brain's cortex.”