Cover legend: Thresholded and colorized video images of a rat whisking á la "Marilyn" by Andy Warhol. The frames were taken at 16 ms intervals as an animal whisked in air. Note the headstage on the rat's head. The different electromyogram across the mystacial pad was recorded as a surrogate of whisking, and the local fields across hippocampus were recorded and used to calculate the current source density for current flow in hippocampus. For more information, see the article by Berg et al. in the June 14, 2006 issue (Vol 26, Issue 24, 6518–6522).