title: Hyperpolarization-activated cyclic nucleotide-gated 1 independent grid cell-phase precession in mice.
abstract: Cell assemblies code information in both the temporal and spatial domain. One tractable example of temporal coding is the phenomenon of phase precession. In medial entorhinal cortex, theta-phase precession is observed in spatially specific grid cells, with grid spike-times shifting to earlier phases of the extracellular theta rhythm as the animal passes through the grid field. Although the exact mechanisms underlying spatial-temporal coding remain unknown, computational work points to single-cell oscillatory activity as a biophysical mechanism capable of producing phase precession. Support for this idea comes from observed correlations between single-cell resonance and entorhinal neurons characterized by phase precession. Here, we take advantage of the absence of single-cell theta-frequency resonance in hyperpolarization-activated cyclic nucleotide-gated (HCN) 1 knockout (KO) mice to examine the relationship between intrinsic rhythmicity and phase precession. We find phase precession is highly comparable between forebrain-restricted HCN1 KO and wild-type mice. Grid fields in HCN1 KO mice display more experience-dependent asymmetry however, consistent with reports of enhanced long-term potentiation in the absence of HCN1 and raising the possibility that the loss of HCN1 improves temporal coding via the rate-phase transformation. Combined, our results clarify the role of HCN1 channels in temporal coding and constrain the number of possible mechanisms generating phase precession. © 2013 Wiley Periodicals, Inc.
authors.affiliation: Kavli Institute for Systems Neuroscience and The Centre for the Biology of Memory, The Norwegian Institute for Technology, Trondheim, Norway; Institute for Interdisciplinary Studies, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: Hannah
authors.initials: H
authors.lastname: Eggink
authors.forename: Paul
authors.initials: P
authors.lastname: Mertens
authors.forename: Eline
authors.initials: E
authors.lastname: Storm
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Giocomo
mesh_terms: D000200:Action Potentials; D000818:Animals; D004569:Electroencephalography; D018728:Entorhinal Cortex / Q000166:cytology / Q000502:physiology*; D005106:Exploratory Behavior; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D017774:Long-Term Potentiation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010507:Periodicity; D015221:Potassium Channels / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012201:Reward; D013037:Spatial Behavior / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*; D013997:Time Factors
chemical_list: C578666:Hcn1 protein, mouse; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015221:Potassium Channels
keywords: HCN1; entorhinal; grid cells; phase precession; temporal codes