title: Theta phase segregation of input-specific gamma patterns in entorhinal-hippocampal networks.
abstract: Precisely how rhythms support neuronal communication remains obscure. We investigated interregional coordination of gamma oscillations using high-density electrophysiological recordings in the rat hippocampus and entorhinal cortex. We found that 30-80 Hz gamma dominated CA1 local field potentials (LFPs) on the descending phase of CA1 theta waves during navigation, with 60-120 Hz gamma at the theta peak. These signals corresponded to CA3 and entorhinal input, respectively. Above 50 Hz, interregional phase-synchronization of principal cell spikes occurred mostly for LFPs in the axonal target domain. CA1 pyramidal cells were phase-locked mainly to fast gamma (>100 Hz) LFP patterns restricted to CA1, which were strongest at the theta trough. While theta phase coordination of spiking across entorhinal-hippocampal regions depended on memory demands, LFP gamma patterns below 100 Hz in the hippocampus were consistently layer specific and largely reflected afferent activity. Gamma synchronization as a mechanism for interregional communication thus rapidly loses efficacy at higher frequencies.
authors.affiliation: New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA; Department of Physics and Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: Erik W
authors.initials: EW
authors.lastname: Schomburg
authors.affiliation: New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA; School of Physics, Complutense University of Madrid, 28040 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Fernández-Ruiz
authors.affiliation: New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA; Allen Institute for Brain Science, Seattle, WA 98103, USA.
authors.forename: Kenji
authors.initials: K
authors.lastname: Mizuseki
authors.affiliation: New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA; MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Department of Physiology, University of Szeged, Szeged 6720, Hungary.
authors.forename: Antal
authors.initials: A
authors.lastname: Berényi
authors.affiliation: Department of Physics and Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA; Allen Institute for Brain Science, Seattle, WA 98103, USA.
authors.forename: Costas A
authors.initials: CA
authors.lastname: Anastassiou
authors.affiliation: Department of Physics and Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA; Allen Institute for Brain Science, Seattle, WA 98103, USA.
authors.forename: Christof
authors.initials: C
authors.lastname: Koch
authors.affiliation: New York University Neuroscience Institute and Center for Neural Science, New York University, New York, NY 10016, USA. Electronic address: gyorgy.buzsaki@nyumc.org.
authors.forename: György
authors.initials: G
authors.lastname: Buzsáki
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D018728:Entorhinal Cortex / Q000502:physiology*; D065818:Gamma Rhythm / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D017966:Pyramidal Cells / Q000502:physiology*; D020318:Rats, Long-Evans; D013826:Theta Rhythm / Q000502:physiology*