The rat in the hat

Wide awake, a rat placed inside a typical brain scanner is too active for images to be recorded. For studies of drug effects on behavior, anesthesia is no alternative. So, Craig L. Woody of Brookhaven National Laboratory in Upton, N.Y., and his colleagues there and at Stony Brook (N.Y.) University are developing a miniature positron-emission tomography, or PET, brain scanner that moves with the rat.