Cover legend: The image shows immunofluorescent labeling of cortical astrocytes stained with GFAP (yellow) and aquaporin 4 (pink). Neurons were stained with MAP2 (blue), and cell nuclei were stained with DAPI (green). The magnification was 60×. Note that GFAP is localized in the cell body and major astrocytic processes, whereas aquaporin 4 is primarily found in the vascular endfeet. Image by NancyAnn Oberheim and Takahiro Takano. For more information, see the article by Lovatt et al. in this issue (pages 12255–12266).