Multiple sclerosis. Scanning electron micrograph of microglial cells (pale, irregular) ingesting oligodendrocytes (smooth, branched). This is the process thought to occur in multiple sclerosis (MS). Oligodendrocytes form insulating myelin sheaths around nerve axons in the central nervous system. Microglia normally ingest cell debris and bacteria as part of the body's immune response. In MS they attack oligodendrocytes, possibly triggered by a virus in people with hereditary susceptibility. Destruction of myelin sheaths leads to loss of nerve function. Symptoms include unsteady gait, visual & speech defects & paralysis Magnification: x1100 at 4.5x6.5inch size.