Brainbow!

Scientists create colorful 'brainbow' images of the nervous system

By activating multiple fluorescent proteins in neurons, neuroscientists at Harvard University are imaging the brain and nervous system as never before, rendering their cells in a riotous spray of colors dubbed a "Brainbow."
Equal parts pointillism, fauvism, and abstract expressionism, the resulting images could also help scientists identify how brain wiring goes awry in many different diseases. Brainbow could also help track the complicated development of the mammalian nervous system, currently understood only in general terms. This, in turn, could elucidate the origins of the many brain disorders that arise early in development.

Drawing upon a mix of genetic tricks and special proteins that cause cells to glow, Brainbow uses a well-known genetic recombination system known as Cre/lox in a new way, to shuffle genes encoding green, yellow, orange, and red fluorescent proteins. The researchers painstakingly assembled the Brainbow transgene from snippets of DNA, and inserted it into neuronal DNA. As they predicted, the cut-and-paste recombination occurred totally at random, in the process assigning scores of different colors to neurons. This variation makes neurons leap out from one another visually under ordinary confocal microscopy.

Full article @ PhysOrg