Cover legend: Neuronal organizaiton of gamma oscillations in space and time. Bistratified (yellow) and oriens-lacunosum moleculare (blue) interneurons, recorded and labeled in rat hippocampal area CA1 in vivo, have distinct firing patterns relative to gamma oscillations (purple waveform). The unexpectedly strong correlation of bistratified interneuron firing to gamma oscillations depicted here suggests a role for gamma oscillations in dendritic processing. Cover designed by Ben Micklem. For more information, see the article by Tukker et al. in this issue (pages 8184–8189).