Email updates

Keep up to date with the latest news and content from BMC Neuroscience and BioMed Central.

This article is part of the supplement: Twentieth Annual Computational Neuroscience Meeting: CNS*2011

Open Access Poster presentation

Dynamical switching between different hippocampal rhythms

Anastasia I Lavrova13*, Ekaterina A Zhuchkova23, Susanne Schreiber23 and Lutz Schimansky-Geier13

Author Affiliations

1 Institute for Physics, Humboldt-Universität zu Berlin, Berlin, 12489, Germany

2 Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany

3 Bernstein Center for Computational Neuroscience, Berlin, 10115, Germany

For all author emails, please log on.

BMC Neuroscience 2011, 12(Suppl 1):P284  doi:10.1186/1471-2202-12-S1-P284


The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2202/12/S1/P284


Published:18 July 2011

© 2011 Lavrova et al; licensee BioMed Central Ltd.

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Poster presentation

The hippocampal circuit can exhibit network oscillations in different frequency ranges (“gamma” - 30-80 Hz; “theta” - 4-12 Hz; as well as “theta/gamma” or a bursting regime) both in vivo and in vitro and switch between them [1]. These different oscillatory modes facilitate memory storage in the hippocampus and memory consolidation [2,3]. The hippocampal neuronal network consists of various types of connected cells that differ in morphology and functional properties, which allows them to provide oscillations with different periods, amplitudes, and phase shifts [1]. Dynamical switching between various rhythms is likely to depend on the local network structure of the neurons.

Our goal is to investigate how coupling strength and delayed propagation influence synchronization and switching between different oscillatory states in minimal neuronal networks. To this end, we constructed a simple model of neurons comprising two fast-spiking and two slow-spiking cells, respectively. Cells are synaptically connected in an all-to-all manner, with exception of the two slow-spiking cells. The network is described by coupled FitzHugh-Nagumo equations that well reproduce the dynamical behavior of different cells types: their periods, amplitudes, and phase shifts.

The model allows us to analyze the influence of synaptic strengths on the network synchronization and dynamical switching between theta, gamma, and bursting regimes. In particular, we perform a thorough bifurcation analysis and identify parameters of synaptic connections that can efficiently induce switches in the network activity. We show that depending on the coupling strengths between slow- and fast-spiking cells, abrupt changes between different rhythms can occur, similar to experimental observations.

Acknowledgments

This work was supported by the BMBF (BCCN Berlin, BPCN).

References

  1. Gloveli T, Kopell N, Dugladze T: Neuronal activity patterns during hippocampal network oscillations in vitro.

    Hippocampal Microcircuits 2010, 5(1):247-276. OpenURL

  2. O’Keefe J, Recce ML: Phase relationship between hippocampal place units and the EEG theta rhythm.

    Hippocampus 1993, 3:317-330. PubMed Abstract | Publisher Full Text OpenURL

  3. Harris KD, Csicsvari J, Hirase H, Dragoi G, Buzsaki G: Organization of cell assemblies in the hippocampus.

    Nature 2003, 424:552-556. PubMed Abstract | Publisher Full Text OpenURL