title: Pyramidal cell-interneuron interactions underlie hippocampal ripple oscillations.
abstract: High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation, frequency control, and spatial coherence of the rhythm are poorly understood. Using multisite optogenetic manipulations in freely behaving rodents, we found that depolarization of a small group of nearby pyramidal cells was sufficient to induce high-frequency oscillations, whereas closed-loop silencing of pyramidal cells or activation of parvalbumin- (PV) or somatostatin-immunoreactive interneurons aborted spontaneously occurring ripples. Focal pharmacological blockade of GABAA receptors abolished ripples. Localized PV interneuron activation paced ensemble spiking, and simultaneous induction of high-frequency oscillations at multiple locations resulted in a temporally coherent pattern mediated by phase-locked interneuron spiking. These results constrain competing models of ripple generation and indicate that temporally precise local interactions between excitatory and inhibitory neurons support ripple generation in the intact hippocampus.
authors.affiliation: NYU Neuroscience Institute, School of Medicine, New York University, New York, NY 10016, USA. Electronic address: eranstark@gmail.com.
authors.forename: Eran
authors.initials: E
authors.lastname: Stark
authors.affiliation: NYU Neuroscience Institute, School of Medicine, New York University, New York, NY 10016, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Roux
authors.affiliation: NYU Neuroscience Institute, School of Medicine, New York University, New York, NY 10016, USA.
authors.forename: Ronny
authors.initials: R
authors.lastname: Eichler
authors.affiliation: NYU Neuroscience Institute, School of Medicine, New York University, New York, NY 10016, USA.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Senzai
authors.affiliation: Korea Institute of Science and Technology, Seoul, South Korea.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Royer
authors.affiliation: NYU Neuroscience Institute, School of Medicine, 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 / Q000187:drug effects / Q000502:physiology; D000818:Animals; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D010320:Parvalbumins / Q000378:metabolism; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013004:Somatostatin / Q000378:metabolism
chemical_list: D058787:GABA-A Receptor Antagonists; D010320:Parvalbumins; D013004:Somatostatin