The thalamus – a structure in the centre of the brain that relays information from the senses – may be responsible for sorting memories before they are stored long term, a study in mice suggests. Previously, the thalamus has been largely overlooked in research on memory processing. Priya Rajasethupathy at the Rockefeller University in New York and her colleagues studied the brain activity of dozens of mice navigating a virtual maze. When the mice's thalamus was stimulated while learning the maze, the animals were able to recall the routes they learned weeks later – by which point they would ordinarily have forgotten. The process of forming and storing memories involves multiple regions of the mammalian brain.