Classically, neuroanatomy has been studied using a variety of tissue-applied stains. Such stains vary in their ability to highlight cells. At one end of the spectrum most of the neurons present are stained to reveal the gross architecture of the brain. Speculations can then be made about the connectivity between those cells that appear to come into close association. At the other end of the spectrum individual cells are stained selectively, revealing the shapes of single cells as though they were taken from their environs.