This video is fascinating and frustrating (from a computational modeling point of view) at the same time. Jeff Lichtman shows in this video (above) the complexity of a tiny little fraction of the mouse brain scanned on a nanometer scale using serial electron microscopy. At 16:00 and the following minutes he shows the relation between the nanometer scale, the complexity that can be observed on this level and the large scale view on the brain. Absolutely impressive.