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Cellular correlate of assembly formation in oscillating hippocampal networks in vitro

Item Type:Article
Title:Cellular correlate of assembly formation in oscillating hippocampal networks in vitro
Creators Name:Baehner, F. and Weiss, E.K. and Birke, G. and Maier, N. and Schmitz, D. and Rudolph, U. and Frotscher, M. and Traub, R.D. and Both, M. and Draguhn, A.
Abstract:Neurons form transiently stable assemblies that may underlie cognitive functions, including memory formation. In most brain regions, coherent activity is organized by network oscillations that involve sparse firing within a well-defined minority of cells. Despite extensive work on the underlying cellular mechanisms, a fundamental question remains unsolved: how are participating neurons distinguished from the majority of nonparticipators? We used physiological and modeling techniques to analyze neuronal activity in mouse hippocampal slices during spontaneously occurring high-frequency network oscillations. Network-entrained action potentials were exclusively observed in a defined subset of pyramidal cells, yielding a strict distinction between participating and nonparticipating neurons. These spikes had unique properties, because they were generated in the axon without prior depolarization of the soma. GABA(A) receptors had a dual role in pyramidal cell recruitment. First, the sparse occurrence of entrained spikes was accomplished by intense perisomatic inhibition. Second, antidromic spike generation was facilitated by tonic effects of GABA in remote axonal compartments. Ectopic spike generation together with strong somatodendritic inhibition may provide a cellular mechanism for the definition of oscillating assemblies.
Keywords:Antidromic Action Potentials, CA1 Pyramidal Cells, Interneurons, Ripples, Animals, Mice
Source:Proceedings of the National Academy of Sciences of the United States of America
Publisher:National Academy of Sciences
Page Range:E607-E616
Date:30 August 2011
Official Publication:https://doi.org/10.1073/pnas.1103546108
PubMed:View item in PubMed

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