Subiculum neurons map the current axis of travel.

Flexible navigation demands knowledge of boundaries, routes and their relationships. Within a multi-path environment, a subpopulation of subiculum neurons robustly encoded the axis of travel. The firing of axis-tuned neurons peaked bimodally, at head orientations 180° apart. Environmental manipulations showed these neurons to be anchored to environmental boundaries but to lack axis tuning in an open arena. Axis-tuned neurons thus provide a powerful mechanism for mapping relationships between routes and the larger environmental context.