Subiculum Encodes Environmental Structure

Subiculum is strongly interconnected with multiple brain regions that together form the brain's distributed cognitive map. The possible functional roles for dorsal subiculum within this system are many, including transmission of the hippocampal map of environmental location, integration of information related to location, orientation, and boundary proximity, and transition of spatial encoding into navigational actions. In this review, we consider evidence for each of these possible roles and contrast them with a potential role for subiculum in the encoding of environmental structure. We conclude that subiculum neuron tuning to boundaries and their orientations, boundary corners and their angles, axes of travel, and structurally analogous locations forms the basis for the encoding of overall environmental shape and the layout of path networks.