For patients with epilepsy, or cancerous brain lesions, sometimes the only way to forward is down. Down past the scalp and into the skull, down through healthy grey matter to get at a tumor or the overactive network causing seizures. At the end of the surgery, all that extra white and grey matter gets tossed in the trash or an incinerator. Well, not all of it. At least, not in Seattle.

For the last few years, doctors at a number of hospitals in the Emerald City have been saving those little bits and blobs of brain, sticking them on ice, and rushing them off in a white van across town to the Allen Institute for Brain Science. Scientists there have been keeping the tissue on life support long enough to tease out how individual neurons look, act, and communicate. And today they’re sharing the first peek at these cells in a freely available public database. It provides a more intimate, intricate look into the circuitry of the human brain than ever before. And it’s just the beginning of a much larger effort to build a complete catalog of human brain cells.

This first release includes electrical readings from a few hundred living neurons—all recently removed from 36 neurosurgery patients in Seattle area hospitals. For 100 of those cells, Allen Institute researchers built 3-D models of their branching structures, which they can use to simulate patterns of pulses and zaps. Scientists can see where in the brain neurons start and stop, and how current flows and spreads a signal throughout a neuronal network—signals that might move a muscle, or make a memory.

Allen Institute for Brain Science

“Thirty minutes ago that was part of someone’s brain, maybe even the part that holds the memory of their first kiss,” says Christof Koch, chief scientist and president of the Allen Institute for Brain Science. “No one has had access like this before, to healthy brain tissue at the level of individual neurons.”

Because of the particular peskiness of studying the human brain, most brain maps are built from mice or post-mortem human tissue. Dead brain cells can tell you a lot about shape; you can stain ‘em and characterize their morphology. But they can’t tell you anything about the function of circuits—because they don’t fire.

So to keep the post-op cells alive and kicking, doctors pack the pea-sized tissue on ice. They need to keep the brain bit as close to freezing as possible—about 4 degrees centigrade—to slow down metabolism and prevent the tissue from deteriorating. Once it arrives at the Allen Institute, researchers slice the sample into many dozens of sections no thinner than a silicon wafer. Each slice is loaded into special containers Allen scientists developed to keep the tissue on life support. They look kind of like little baskets, floating around a tiny pump that bubbles in a life-sustaining stream of oxygen.