Microglia are a type of cell found in the central nervous system, specifically within the brain and spinal cord. They are part of the immune system and play an important role in maintaining the health of the nervous system by monitoring for any damage or injury to neurons. Microglia act as the first responders to such events and help to clear away debris from injured areas, release cytokines to recruit other immune cells, and initiate a healing process. They also play a role in synaptic pruning during development and have been implicated in various neurological disorders including Alzheimer's disease, Parkinson's disease, and multiple sclerosis.