title: Effects of Arc/Arg3.1 gene deletion on rhythmic synchronization of hippocampal CA1 neurons during locomotor activity and sleep.
abstract: The activity-regulated cytoskeletal-associated protein/activity regulated gene (Arc/Arg3.1) is crucial for long-term synaptic plasticity and memory formation. However, the neurophysiological substrates of memory deficits occurring in the absence of Arc/Arg3.1 are unknown. We compared hippocampal CA1 single-unit and local field potential (LFP) activity in Arc/Arg3.1 knockout and wild-type mice during track running and flanking sleep periods. Locomotor activity, basic firing and spatial coding properties of CA1 cells in knockout mice were not different from wild-type mice. During active behavior, however, knockout animals showed a significantly shifted balance in LFP power, with a relative loss in high-frequency (beta-2 and gamma) bands compared to low-frequency bands. Moreover, during track-running, knockout mice showed a decrease in phase locking of spiking activity to LFP oscillations in theta, beta and gamma bands. Sleep architecture in knockout mice was not grossly abnormal. Sharp-wave ripples, which have been associated with memory consolidation and replay, showed only minor differences in dynamics and amplitude. Altogether, these findings suggest that Arc/Arg3.1 effects on memory formation are not only manifested at the level of molecular pathways regulating synaptic plasticity, but also at the systems level. The disrupted power balance in theta, beta and gamma rhythmicity and concomitant loss of spike-field phase locking may affect memory encoding during initial storage and memory consolidation stages.
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Hemi A I
authors.initials: HA
authors.lastname: Malkki
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Paul E C
authors.initials: PE
authors.lastname: Mertens
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Jan V
authors.initials: JV
authors.lastname: Lankelma
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Vinck
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: van Schalkwijk
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Laura B
authors.initials: LB
authors.lastname: van Mourik-Donga
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands.
authors.forename: Francesco P
authors.initials: FP
authors.lastname: Battaglia
authors.affiliation: Institute for Molecular and Cellular Cognition Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Falkenried 94, 20251 Hamburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Mahlke
authors.affiliation: Institute for Molecular and Cellular Cognition Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Falkenried 94, 20251 Hamburg, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Kuhl
authors.affiliation: Cognitive & Systems Neuroscience, Swammerdam Institute, Center for Neuroscience, University of Amsterdam, The Netherlands; Research Priority Program Brain and Cognition, University of Amsterdam, Postal Box 94216, 1090 GE Amsterdam, The Netherlands. Electronic address: C.M.A.Pennartz@uva.nl.
authors.forename: Cyriel M A
authors.initials: CM
authors.lastname: Pennartz
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000502:physiology*; D058407:Electroencephalography Phase Synchronization / Q000502:physiology*; D065818:Gamma Rhythm / Q000502:physiology*; D017781:Genes, Immediate-Early; D008568:Memory / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D012890:Sleep / Q000502:physiology*
chemical_list: D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; C092069:activity regulated cytoskeletal-associated protein
keywords: Gamma rhythm; Immediate early gene; Memory; Phase locking; Synaptic plasticity; Theta rhythm