A multiregional brain circuit allows larval zebrafish to track where they are, where they’ve been, and how to get back to their original location after being displaced, researchers report December 22 in the journal Cell. The results shed light on how larval zebrafish track their own location and use that to navigate after being pushed off course by currents. Many animals keep track of where they are in their environment. They use self-location information for many important behaviours, such as efficiently returning to safe locations after visiting unknown and potentially dangerous areas, revisiting food-rich areas, and avoiding foraging in food-poor areas. While self-location is represented in the hippocampal formation, it is unknown how such representations arise, whether they exist in more ancient brain regions, and by what pathways they control locomotion. Whole-brain functional imaging revealed not only the existence of positional homeostasis in larval zebrafish, but also how the brain identifies and corrects changes in zebrafish location. The underlying circuit computes self-location in the dorsal brainstem by integrating visual information to form a memory of past displacements as the animal actively or passively changes its location. This self-location representation is read out by the inferior olive as a long-lasting positional error signal, reflecting the difference between the fish’s original and current position. This signal is transformed into locomotor output that corrects for accumulated displacements over the course of many seconds.