title: Speed cells in the medial entorhinal cortex.
abstract: Grid cells in the medial entorhinal cortex have spatial firing fields that repeat periodically in a hexagonal pattern. When animals move, activity is translated between grid cells in accordance with the animal's displacement in the environment. For this translation to occur, grid cells must have continuous access to information about instantaneous running speed. However, a powerful entorhinal speed signal has not been identified. Here we show that running speed is represented in the firing rate of a ubiquitous but functionally dedicated population of entorhinal neurons distinct from other cell populations of the local circuit, such as grid, head-direction and border cells. These 'speed cells' are characterized by a context-invariant positive, linear response to running speed, and share with grid cells a prospective bias of ∼50-80 ms. Our observations point to speed cells as a key component of the dynamic representation of self-location in the medial entorhinal cortex.
authors.affiliation: 1] Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres gate 9, MTFS, 7491 Trondheim, Norway [2] Leloir Institute, IIBBA - CONICET, Buenos Aires, C1405BWE, Argentina.
authors.forename: Emilio
authors.initials: E
authors.lastname: Kropff
authors.affiliation: Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres gate 9, MTFS, 7491 Trondheim, Norway.
authors.forename: James E
authors.initials: JE
authors.lastname: Carmichael
authors.affiliation: Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres gate 9, MTFS, 7491 Trondheim, Norway.
authors.forename: May-Britt
authors.initials: MB
authors.lastname: Moser
authors.affiliation: Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian University of Science and Technology, Olav Kyrres gate 9, MTFS, 7491 Trondheim, Norway.
authors.forename: Edvard I
authors.initials: EI
authors.lastname: Moser
mesh_terms: D000054:Acceleration; D000200:Action Potentials / Q000502:physiology; D000818:Animals; D018728:Entorhinal Cortex / Q000166:cytology* / Q000502:physiology*; D004777:Environment; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012420:Running / Q000502:physiology* / Q000523:psychology*; D013997:Time Factors