Here, three mouse neurons are each tinted a different color, so that the surfaces of their cell bodies, dendrites, and axons are visible. The gray "base" is the raw electron microscope image. Eventually, Seung hopes to train systems of computers, using artificial intelligence, to create images like this one automatically, speeding the tedious process of mapping a connectome. Adding to the challenge, Seung says, is the fact that an individual's connectome changes over time as neurons grow new branches and prune old ones in response to experiences.