Cover picture: Visualization of Ca²⁺ calmodulin-dependent protein kinase II (CaMKII) activation in a dendritic segment of a cultured hippocampal neuron using a fluorescence resonance energy transfer (FRET)-based probe, Camuiα. The time-lapse images were taken every 5 min using a two-photon microscope and are shown in intensity-modulated display mode; warmer hues indicate a higher cyan fluorescent protein (CFP)/yellow fluorescent protein (YFP) ratio or higher CaMKII activity, and brightness indicates that of the CFP channel. A 20 µ m concentration of glutamate activated CaMKII in the ninth frame. For details, see the article by Takao et al. in this issue (pages 3107–3112).