Two main classes of them include astrocytes and oligodendrocytes.  
Primary brain tumors result from their out of control reproduction, and their ependymal variety is thought to play a role in the blood brain barrier.  Two main classes of them include astrocytes and oligodendrocytes.  They are destroyed at the sites of multiple sclerosis lesions, so that damaged myelin is not repaired by their Schwann type.  Smaller than neurons and 5 to 50 times more numerous, they make up half the volume of the central nervous system.  FTP, name these cells that nourish and support other brain cells, perhaps named because of the postulate that they are the "glue" holding nervous tissues together.
Primary brain tumors result from their out of control reproduction, and their ependymal variety is thought to play a role in the blood brain barrier.  
glial cells or glia or neuroglia