Cover picture: Five Ca²⁺ syntillas (from scintilla, L., spark, in a synaptic structure, a nerve terminal) as imaged using the Ca²⁺ indicator fluo-3 in the cytosol of an isolated terminal from a single mouse hypothalamic neuron. Each panel shows a single syntilla, all arising in the same terminal. The circular outline of the terminal can be seen on the square blue background. Syntillas arise from intraterminal Ca²⁺ stores, are mediated by ryanodine receptors, and are increased in frequency by physiological levels of depolarization in the absence of Ca²⁺ influx. The diameter of the nerve terminal is 8 µm. For details, see the article by De Crescenzo et al. in this issue (pages 1226–1235).