The decades-old anesthetic ketamine could be a game changer for treating severe depression, but there are still many questions about how the drug works, including exactly how it affects the brain's cells and circuits.

By taking advantage of a 'giving up' behavior exhibited by zebrafish, the ability to image the fish's entire brain, and a unique virtual reality system, a team of researchers found where ketamine acts in the zebrafish brain: at supporting cells called astroglia, rather than neurons.