The brain's wiring diagram is a map of information paths, containing the brain's software. The first wiring diagram of an entire brain (published in 1986) came from the roundworm C. elegans
with its few hundred neurons. In contrast, the mouse brain has almost 100 million and the human brain about 100 billion neurons. Nevertheless, today it is no longer unthinkable to obtain at least a mouse brain's diagram. The first step on this path is already made: the development of a preparation with sufficient resolution and contrast. Work on methods for cutting, imaging, and analysis is in progress.