These neurons aren’t the lion’s share of the brain. A lot of the volume of the brain is consumed by a set of cells called the glia—comprising 80 percent of the brain, Dr. Barres told me. Broadly, glia are non-neuronal cells. These glia are central to the immune function of the brain. The glia come in three flavors: astrocytes, oligodendrocytes, and microglia.
Because of the blood/brain barrier, scientists thought, for a long time, that immunity didn't exist in the brain. Enter: the glia cells. These babies may end up revolutionizing modern medicine and our treatment/understanding of inflammatory disease as we know it!
