To enable navigation, the brain must represent and integrate the geometric features of our surroundings. Sun et al. have identified neurons in the mouse subiculum that encode corners.

Subiculum neurons encode the locations of environmental boundaries and objects. Sun et al. asked whether this brain region also encodes corner locations. Measuring spikes in calcium signals (a proxy for neuronal firing) in freely moving mice as they explored arenas with different numbers of corners revealed that a subset of subiculum neurons specifically increase their firing when an animal is close to a corner.