Microglia brain cells involved in the first level defenses against brain infections have been thought to worsen prion diseases by secreting toxic molecules that can damage nerves. Experimental drug PLX5622 tested against the role of microglia against scrapie, has been shown to kill most of the microglia in the brain fairly quickly, model mice given PLX5622 microglia were eliminated and mice died a month quicker than untreated, hinting that microglia can defend against prion infections and slow the course of the disease.
Drugs which increase beneficial activity of microglia may help in slowing progression of prion diseases. Additional studies are in progress to investigate how, what, when, and why microglia may be able to destroy prions within the brain to find out if the hypothesis of microglia trap and destroying aggregated prion protein which cause brain damage was true. It was noted that microglia may have similar benefit to other neurodegenerative diseases that are associated with protein aggregation.