File:In-Vivo-Imaging-Reveals-Distinct-Inflammatory-Activity-of-CNS-Microglia-versus-PNS-Macrophages-in-a-pone.0017910.s001.ogv

English: Microglial reaction towards single axon transection in the spinal cord lateral column of control mice. The experiments were performed in double transgenic mice expressing EGFP in microglia and EYFP in projection neurons. Microglia are depicted in green while, for better visualization and distinction, axons are shown in red. All videos are arranged such that rostral is to the left side. This video sequence (105 minutes length) lasts from 45 minutes before to 60 minutes after a laser-induced axonal transection (the injury was set at 0 min). It shows microglial reaction towards the site of the injury (note the autofluorescence as speckles in the image center; marked by arrow). Surrounding microglia immediately extended their processes forming a shielding ring around the injury. The transection led to an acute axonal degeneration at both sides of the injury, indicated by interruptions and bulb-like swellings. Within the recorded time-lapse sequence of 60 minutes after injury, reacting microglial cells polarized and began to migrate in an ameboid manner towards the injured axon. No phagocytic activity of microglia was observed within the first hour after the injury. Note the monocytes within the blood vessels. The control mouse was 90 days of age. The video sequence corresponds to a time-lapse series of 53 stacks of images. Each of these stacks is shown as a maximum intensity projection (MIP). The frame rate of the video is about 2 minutes per MIP. Scale bar, 20 µm.