The image above is of a mouse-brain. The edges of art and science can blur in the hands of innovators:
Previous techniques for highlighting neurons used at most two colors. One common approach developed in 1873 by an Italian physician and still used today, called the Golgi method, stains neurons in their entirety but only affects a few brain cells at a time.
In contrast, Brainbow allows researchers to tag several hundred neurons at once with roughly 90 distinct colors. The resulting images , which resemble abstract color paintings, are both beautiful and informative. They look like they could hang in a modern art museum and are among the most detailed images of neuronal connections ever made.
More on the technique here.