Cover picture: Light-evoked calcium increase in glial cells of the rat retina. This montage of a pseudocolor Ca²⁺ fluorescence image shows the Ca²⁺ increase in Muller glial cells 4 s after a light stimulus was turned on. Muller cell processes (yellow, red, and white areas) surround ganglion cell somata (blue areas). The experiment demonstrates that a natural stimulus can evoke Ca²⁺ increases in CNS glia. For details, see the article by Newman in the June 8, 2005 issue (pages 5502–5510).