Context from wikipedia,
>Microglia are a type of neuroglia (glial cell) located throughout the brain and spinal cord. Microglia account for 10–15% of all cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune defence in the central nervous system (CNS).
[Pure gif version](https://thumbs.gfycat.com/MajesticEvilHectorsdolphin-size_restricted.gif).
[Super-Resolution Imaging of the Extracellular Space in Living Brain Tissue](http://www.cell.com/cell/fulltext/S0092-8674%2818%2930151-X) (cell.com link).
Context from wikipedia,
>Microglia are a type of neuroglia (glial cell) located throughout the brain and spinal cord. Microglia account for 10–15% of all cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune defence in the central nervous system (CNS).