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Coherent phasic excitation during hippocampal ripples

Item Type:Article
Title:Coherent phasic excitation during hippocampal ripples
Creators Name:Maier, N. and Tejero-Cantero, A. and Dorrn, A.L. and Winterer, J. and Beed, P.S. and Morris, G. and Kempter, R. and Poulet, J.F.A. and Leibold, C. and Schmitz, D.
Abstract:High-frequency hippocampal network oscillations, or "ripples," are thought to be involved in episodic memory. According to current theories, memory traces are represented by assemblies of principal neurons that are activated during ripple-associated network states. Here we performed in vivo and in vitro experiments to investigate the synaptic mechanisms during ripples. We discovered postsynaptic currents that are phase-locked to ripples and coherent among even distant CA1 pyramidal neurons. These fast currents are consistent with excitatory postsynaptic currents (EPSCs) as they are observed at the equilibrium potential of Cl(-), and they display kinetics characteristic of EPSCs. Furthermore, they survived after intracellular blockade of GABAergic transmission and are effective to regulate the timing of action potentials. In addition, our data show a progressive synchronization of phasic excitation and inhibition during the course of ripples. Together, our results demonstrate the presence of phasic excitation during ripples reflecting an exquisite temporal coordination of assemblies of active pyramidal cells.
Keywords:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid, Action Potentials, Brain Waves, Excitatory Postsynaptic Potentials, GABA Antagonists, Hippocampus, Neural Inhibition, Pyramidal Cells, Synaptic Transmission, gamma-Aminobutyric Acid, Animals, Mice
Publisher:Cell Press
Page Range:137-152
Date:6 October 2011
Official Publication:https://doi.org/10.1016/j.neuron.2011.08.016
PubMed:View item in PubMed

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