A team of Harvard scientists implanted genes into mice that coded for three color fluorescing proteins in their brains, and had them randomly express themselves, producing up to 90 different color shades. The image above, dubbed the Brainbow, was created using the technique, and the New York Times describes the motivation for the research:
For an organ that has been scanned millions of times by experts using high-end imaging technology, the brain remains in large part a shrouded landscape, as lost in darkness as the ocean floor.
One reason has less to with the brain’s complexity than its uniformity: it contains billions of identical-looking cells, most sprouting multiple identical-looking branches to other cells, near and far. A needle in a haystack at least looks different from the strands around it; finding and mapping large numbers of neurons is more like working out the root system beneath a tropical rain forest.
But last week, researchers at Harvard published pictures in which all those anonymous gray cells glowed in distinctive colors, like a bougainvillea bush gone haywire.