Microglia

Microglia are like specialized macrophages capable of phagocytosis that protect neurons of the central nervous system. They are derived from hematopoietic precursors rather than ectodermal tissue; they are commonly categorized as such because of their supportive role to neurons. These cells comprise approximately 15% of the total cells of the central nervous system. They are found in all regions of the brain and spinal cord. Microglial cells are small relative to macroglial cells, with changing shapes and oblong nuclei. They are mobile within the brain and multiply when the brain is damaged. In the healthy central nervous system, microglia processes constantly sample all aspects of their environment (neurons, macroglia and blood vessels).

Eating Berries May Activate the Brain's Natural Housekeeper for Healthy Aging

http://www.sciencedaily.com/releases/2010/08/100823142927.htm

http://en.wikipedia.org/wiki/Glial_cell#Macroglia

http://en.wikipedia.org/wiki/Microglia

How Some Brain Cells Hook Up Surprises Researchers: The Untold Secret Life of the Humble Microglia http://www.sciencedaily.com/releases/2010/11/101102171608.htm