title: Grid cells use HCN1 channels for spatial scaling.
abstract: Entorhinal grid cells have periodic, hexagonally patterned firing locations that scale up progressively along the dorsal-ventral axis of medial entorhinal cortex. This topographic expansion corresponds with parallel changes in cellular properties dependent on the hyperpolarization-activated cation current (Ih), which is conducted by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. To test the hypothesis that grid scale is determined by Ih, we recorded grid cells in mice with forebrain-specific knockout of HCN1. We find that, although the dorsal-ventral gradient of the grid pattern was preserved in HCN1 knockout mice, the size and spacing of the grid fields, as well as the period of the accompanying theta modulation, was expanded at all dorsal-ventral levels. There was no change in theta modulation of simultaneously recorded entorhinal interneurons. These observations raise the possibility that, during self-motion-based navigation, Ih contributes to the gain of the transformation from movement signals to spatial firing fields.
authors.affiliation: Kavli Institute for Systems Neuroscience and Centre for the Biology of Memory, Norwegian University of Science and Technology, 7030 Trondheim, Norway. lisa.m.giocomo@ntnu.no
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Giocomo
authors.forename: Syed A
authors.initials: SA
authors.lastname: Hussaini
authors.forename: Fan
authors.initials: F
authors.lastname: Zheng
authors.forename: Eric R
authors.initials: ER
authors.lastname: Kandel
authors.forename: May-Britt
authors.initials: MB
authors.lastname: Moser
authors.forename: Edvard I
authors.initials: EI
authors.lastname: Moser
mesh_terms: D000818:Animals; D001931:Brain Mapping; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics / Q000378:metabolism*; D018728:Entorhinal Cortex / Q000166:cytology* / Q000502:physiology*; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007395:Interneurons; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D054815:Cyclic Nucleotide-Gated Cation Channels; C578666:Hcn1 protein, mouse; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015221:Potassium Channels