Microglia are a type of cell found in the brain and spinal cord. They account for up to 15% of all cells within the brain, and function as the first line of immunity to the central nervous system.

Microglia play a very important role in the brain – acting as the brain’s natural cleaner, removing debris and damaging particles. These particles include plaque, unnecessary neurons, damaged particles, and infectious agents. The microglia must be able to quickly identify potentially damaging agents and ingest them.

While removing debris in a brain with Alzheimer’s pathology, the microglia may become overactive and also remove healthy cells such as synapses, resulting in increased damage to the brain.