From Nature:
It’s not often that research results look this good. An elegant new way to visualize individual brain cells not only provides a major boost to scientists trying to understand how the brain works, but has also won one of its developers a major prize in science photography. The method — described by neuroscientists at Harvard University in Cambridge, Massachusetts, in today’s Nature — allows researchers to see more clearly how individual neurons connect with each other by colouring each one from a palette of about 90 shades. In this way they will be able to build up a detailed diagram of the brain’s wiring, which will help to study how it computes.
More than a century ago, neuroscientists developed the first method of staining individual neurons — with silver chromate. Work with this technique was the basis of the Nobel Prize in Physiology or Medicine in 1906. But this could only stain neurons with one colour. Only in the last decade have scientists improved on this technique, using genetic engineering to transfer genes for fluorescent proteins into mice such that they are expressed in neurons. But until now they could transfer no more than two florescent-protein genes at a time, lighting up the brain with two colours. “It was clear that two colours were not enough to map connections efficiently in the brain’s complex tangle of neurons,” says Joshua Sanes, one of the paper’s senior scientists.
More here.