Transplanting human brain cells into mice makes the mice smarter, a new study shows.
But the smart-making brain cells are not the nerve cells most people think of as controlling thoughts. Instead, they are part of the supporting cast of brain cells known as glia (Greek for “glue”).
Scientists have long seen glia, including a subset known as astrocytes, as support cells that feed neurons, mop up excess neurotransmitters and generally help hold the brain together. The new study, published March 7 in Cell Stem Cell, shows that glial cells also influence memory formation and could change how scientists think the brain works, says R. Douglas Fields of the National Institute of Child Health and Human Development. “It’s a paradigm-shifting paper,” says Fields, who was not involved in the work.
In the new study, researchers led by neurologist and stem cell biologist Steven Goldman and neurobiologist Maiken Nedergaard of the University of Rochester Medical Center in New York implanted human cells called glial progenitor cells into the brains of newborn mice. Glial progenitor cells are a type of stem cell that is poised to make several varieties of glia, including astrocytes. Previously, the researchers had transplanted human glial progenitor cells into the brains of mice that had a genetic disorder mimicking multiple sclerosis. The glial progenitor cells healed the mice, allowing them to live a normal life span. That result held promise that such cell transplants might help people with neurological disorders.