• Astrocytes (play a role in normal mental function in a healthy brain)
  • Microglia (protect the brain from injury and disease)
  • Oligodendrocytes (form myelin insulation on axons in the brain and spinal cord)
  • Schwann (form myelin insulation on selected axons outside the brain and spinal cord)

(Fields, R. Douglas, PhD. The Other Brain. pp 20-38. NY: Simon & Schuster, 2009.)