title: During Running in Place, Grid Cells Integrate Elapsed Time and Distance Run.
abstract: The spatial scale of grid cells may be provided by self-generated motion information or by external sensory information from environmental cues. To determine whether grid cell activity reflects distance traveled or elapsed time independent of external information, we recorded grid cells as animals ran in place on a treadmill. Grid cell activity was only weakly influenced by location, but most grid cells and other neurons recorded from the same electrodes strongly signaled a combination of distance and time, with some signaling only distance or time. Grid cells were more sharply tuned to time and distance than non-grid cells. Many grid cells exhibited multiple firing fields during treadmill running, parallel to the periodic firing fields observed in open fields, suggesting a common mode of information processing. These observations indicate that, in the absence of external dynamic cues, grid cells integrate self-generated distance and time information to encode a representation of experience.
authors.affiliation: Center for Memory and Brain, Boston University, Boston, MA 02215, USA. Electronic address: bkraus@bu.edu.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Kraus
authors.affiliation: Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, QC H4H 1R3, Canada.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Brandon
authors.affiliation: Center for Memory and Brain, Boston University, Boston, MA 02215, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Robinson
authors.affiliation: Center for Memory and Brain, Boston University, Boston, MA 02215, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Connerney
authors.affiliation: Center for Memory and Brain, Boston University, Boston, MA 02215, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hasselmo
authors.affiliation: Center for Memory and Brain, Boston University, Boston, MA 02215, USA. Electronic address: hbe@bu.edu.
authors.forename: Howard
authors.initials: H
authors.lastname: Eichenbaum
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D004567:Electrodes, Implanted; D018728:Entorhinal Cortex / Q000166:cytology* / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D012420:Running / Q000502:physiology*; D013997:Time Factors