Lisa M Giocomo1, Tor Stensola2, Tora Bonnevie2, Tiffany Van Cauter2, May-Britt Moser2, Edvard I Moser3. 1. Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian Brain Center, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7491 Trondheim, Norway. Electronic address: giocomo@stanford.edu. 2. Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian Brain Center, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7491 Trondheim, Norway. 3. Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Norwegian Brain Center, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7491 Trondheim, Norway. Electronic address: edvard.moser@ntnu.no.
Abstract
BACKGROUND: Neural circuits in the medial entorhinal cortex (MEC) support translation of the external environment to an internal map of space, with grid and head direction neurons providing metrics for distance and orientation. RESULTS: We show here that head direction cells in MEC are organized topographically. Head direction tuning varies widely across the entire dorsoventral MEC axis, but in layer III there is a gradual dorsal-to-ventral increase in the average width of the directional firing field. Sharply tuned cells were encountered only at the dorsal end of MEC. Similar topography was not observed among head direction cells in layers V-VI. At all MEC locations, in all layers, the preferred firing direction (directional phase) showed a uniform distribution. The continuity of the dorsoventral tuning gradient coexisted with discrete topography in the spatial scale of simultaneously recorded grid cells. CONCLUSIONS: The findings point to dorsoventral gradients as a fundamental property of entorhinal circuits, upon which modular organization may be expressed in select subpopulations.
BACKGROUND: Neural circuits in the medial entorhinal cortex (MEC) support translation of the external environment to an internal map of space, with grid and head direction neurons providing metrics for distance and orientation. RESULTS: We show here that head direction cells in MEC are organized topographically. Head direction tuning varies widely across the entire dorsoventral MEC axis, but in layer III there is a gradual dorsal-to-ventral increase in the average width of the directional firing field. Sharply tuned cells were encountered only at the dorsal end of MEC. Similar topography was not observed among head direction cells in layers V-VI. At all MEC locations, in all layers, the preferred firing direction (directional phase) showed a uniform distribution. The continuity of the dorsoventral tuning gradient coexisted with discrete topography in the spatial scale of simultaneously recorded grid cells. CONCLUSIONS: The findings point to dorsoventral gradients as a fundamental property of entorhinal circuits, upon which modular organization may be expressed in select subpopulations.
Authors: Jon W Rueckemann; Audrey J DiMauro; Lara M Rangel; Xue Han; Edward S Boyden; Howard Eichenbaum Journal: Hippocampus Date: 2015-10-01 Impact factor: 3.899
Authors: Verner P Bingman; Scott A MacDougall-Shackleton Journal: J Comp Physiol A Neuroethol Sens Neural Behav Physiol Date: 2017-03-16 Impact factor: 1.836