"Brainbow" zebrafish. Neurons are labeled in multiple colors with "Brainbow" (Nature, 2007) fluorescence microscopy. Three fluorescent proteins (cyan, yellow, and red) are randomly taken up by various neurons, offering a palette of dozens of colors to help scientists follow complex neural pathways. Shown here is a 5-day-old zebrafish larva viewed from the dorsal side, captured using a 20X objective. Fourth Prize, 2008 Olympus BioScapes Digital Imaging Competition®.