Brain Under Surveillance: The Microglia Patrol

Abstract
The environment that cells encounter within tissues is extremely complex and virtually impossible to reconstitute in vitro. Two-photon microscopy on tissues of living animals is rapidly revealing the behavior of cells in their natural environment. In their Perspective, Fetler and Amigorena discuss two recent papers that use this powerful imaging technique to observe the dynamic behavior of microglial cells in a live mouse brain before and after brain injury.