Boundary coding in the rat subiculum

Stewart, S.; Jeewajee, A.; Wills, T.J.; Burgess, N.; Lever, C.

Abstract

The spatial mapping function of the hippocampal formation is likely derived from two sets of information: one based on the external environment and the other based on self-motion. Here, we further characterize ‘boundary vector cells’ (BVCs) in the rat subiculum, which code space relative to one type of cue in the external environment: boundaries. We find that the majority of cells with fields near the perimeter of a walled environment exhibit an additional firing field when an upright barrier is inserted into the walled environment in a manner predicted by the BVC model. We use this property of field repetition as a heuristic measure to define BVCs, and characterize their spatial and temporal properties. In further tests, we find that subicular BVCs typically treat drop edges similarly to walls, including exhibiting field repetition when additional drop-type boundaries are added to the testing environment. In other words, BVCs treat both kinds of edge as environmental boundaries, despite their dissimilar sensory properties. Finally, we also report the existence of ‘boundary-off cells’, a new class of boundary-coding cells. These cells fire everywhere except where a given BVC might fire.

Citation

Stewart, S., Jeewajee, A., Wills, T., Burgess, N., & Lever, C. (2014). Boundary coding in the rat subiculum. Philosophical Transactions of the Royal Society B: Biological Sciences, 369(1635), Article 20120514. https://doi.org/10.1098/rstb.2012.0514

• Journal Article Type: Article
• Acceptance Date: Dec 20, 2013
• Online Publication Date: Feb 5, 2014
• Publication Date: Feb 5, 2014
• Deposit Date: Jan 18, 2017
• Publicly Available Date: Jan 18, 2017
• Journal: Philosophical Transactions of the Royal Society B: Biological Sciences
• Print ISSN: 0962-8436
• Electronic ISSN: 1471-2970
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 369
• Issue: 1635
• Article Number: 20120514
• DOI: https://doi.org/10.1098/rstb.2012.0514
• Public URL: https://durham-repository.worktribe.com/output/1367165