Astrocyte elevated gene-1 (AEG-1) colocalizes with reactive astrocytes during astrogliosis. AEG-1 expression in activated astrocytes of mouse brain, 4 days post stereotactic phosphate-buffered saline (PBS) injection, was analyzed by immunofluorescent microscopy. The non-injected contralateral hemisphere was used as a control. Immunostaining for glial fibrillary acidic protein (GFAP) (red, astrocyte marker) and 4', 6-diamidino-2-phenylindole (DAPI) (blue, nuclear marker) identified the needle tract of activated astrocytes (A,B). Non-injected (inset image, (C) and PBS-injected contralateral hemispheres costained for AEG-1 and GFAP, were assessed for AEG-1 expression and colocalization with GFAP (yellow, inset image, (D).