NPR's Jon Hamilton reports on research showing how ketamine altered the brain of a zebrafish. JON HAMILTON, BYLINE: In people, a single dose of ketamine can keep depression at bay for weeks.

A tiny fish is helping scientists understand how the anesthetic drug ketamine relieves depression. NPR's Jon Hamilton reports on research showing how ketamine altered the brain of a zebrafish. JON ...

New research shows that the anesthetic ketamine keeps fish from giving up -- and the way it works may help figure out how it works in humans and lead to better medications for depression.