title: Head direction is coded more strongly than movement direction in a population of entorhinal neurons.
abstract: The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/s and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. This article is part of a Special Issue entitled SI: Brain and Memory.
authors.affiliation: Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA; Center of Excellence for Learning in Education, Science, and Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA. Electronic address: fraudies@bu.edu.
authors.forename: Florian
authors.initials: F
authors.lastname: Raudies
authors.affiliation: Division of Biological Science, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA 92093-0357, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Brandon
authors.affiliation: Department of Psychological and Brain Sciences, Center for Systems Neuroscience and Graduate Program for Neuroscience, Boston University, 2 Cummington Street, Boston, MA 02215, USA.
authors.forename: G William
authors.initials: GW
authors.lastname: Chapman
authors.affiliation: Center for Computational Neuroscience and Neural Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA; Center of Excellence for Learning in Education, Science, and Technology, Boston University, 677 Beacon Street, Boston, MA 02115, USA; Department of Psychological and Brain Sciences, Center for Systems Neuroscience and Graduate Program for Neuroscience, Boston University, 2 Cummington Street, Boston, MA 02215, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hasselmo
mesh_terms: D000818:Animals; D018728:Entorhinal Cortex / Q000502:physiology*; D006257:Head / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D009068:Movement; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D065854:Spatial Navigation / Q000502:physiology*
keywords: Attractor model; Entorhinal cortex; Grid cell; Movement direction; Velocity controlled oscillator model