title: Reconceiving the hippocampal map as a topological template.
abstract: The role of the hippocampus in spatial cognition is incontrovertible yet controversial. Place cells, initially thought to be location-specifiers, turn out to respond promiscuously to a wide range of stimuli. Here we test the idea, which we have recently demonstrated in a computational model, that the hippocampal place cells may ultimately be interested in a space's topological qualities (its connectivity) more than its geometry (distances and angles); such higher-order functioning would be more consistent with other known hippocampal functions. We recorded place cell activity in rats exploring morphing linear tracks that allowed us to dissociate the geometry of the track from its topology. The resulting place fields preserved the relative sequence of places visited along the track but did not vary with the metrical features of the track or the direction of the rat's movement. These results suggest a reinterpretation of previous studies and new directions for future experiments.
authors.affiliation: The Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States Baylor College of Medicine, Houston, United States dabaghia@bcm.edu.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Dabaghian
authors.affiliation: The Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States Baylor College of Medicine, Houston, United States.
authors.forename: Vicky L
authors.initials: VL
authors.lastname: Brandt
authors.affiliation: Sloan-Swartz Center for Theoretical Neurobiology, W.M. Keck Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States Department of Physiology, University of California, San Francisco, San Francisco, United States.
authors.forename: Loren M
authors.initials: LM
authors.lastname: Frank
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001931:Brain Mapping; D002450:Cell Communication; D003071:Cognition / Q000502:physiology; D003214:Conditioning, Classical; D004215:Distance Perception / Q000502:physiology*; D004566:Electrodes; D006624:Hippocampus / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D011984:Sensory Receptor Cells / Q000166:cytology / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013238:Stereotaxic Techniques
keywords: geometry; hippocampus; place cells; spatial learning; topology