Synaptic mechanisms of pattern completion in the hippocampal CA3 network Journal Article


Author(s): Guzman, Segundo J; Schlögl, Alois; Frotscher, Michael; Jonas, Peter
Article Title: Synaptic mechanisms of pattern completion in the hippocampal CA3 network
Affiliation IST Austria
Abstract: The hippocampal CA3 region plays a key role in learning and memory. Recurrent CA3–CA3 synapses are thought to be the subcellular substrate of pattern completion. However, the synaptic mechanisms of this network computation remain enigmatic. To investigate these mechanisms, we combined functional connectivity analysis with network modeling. Simultaneous recording fromup to eight CA3 pyramidal neurons revealed that connectivity was sparse, spatially uniform, and highly enriched in disynaptic motifs (reciprocal, convergence,divergence, and chain motifs). Unitary connections were composed of one or two synaptic contacts, suggesting efficient use of postsynaptic space. Real-size modeling indicated that CA3 networks with sparse connectivity, disynaptic motifs, and single-contact connections robustly generated pattern completion.Thus, macro- and microconnectivity contribute to efficient memory storage and retrieval in hippocampal networks.
Journal Title: Science
Volume: 353
Issue 6304
ISSN: 0036-8075
Publisher: American Association for the Advancement of Science  
Date Published: 2016-09-09
Start Page: 1117
End Page: 1123
Sponsor: Supported by the Fond zur Förderung der Wissenschaftlichen Forschung (P 24909-B24 to P.J.), the European Union (European Research Council Advanced Grant 268548 to P.J.), and the Deutsche Forschungsgemeinschaft (FR 620/14-1 to M.F.).
URL:
DOI: 10.1126/science.aaf1836
Notes: We thank A. Aertsen, J. Csicsvari, A. Roth, C. Savin, R. Shigemoto, and two anonymous reviewers for critically reading the manuscript, as well as J. Szabadics and S. Rotter for useful discussions. We are grateful to F. Marr for excellent technical assistance, B. Joch for help with morphological analysis, E. Kramberger for manuscript editing, T. Asenov (Miba machine shop) for technical support, and M. Schunn (preclinical facility) for animal maintenance. We also thank the scientific computing facilities, University of Innsbruck, for help with the MACH computer cluster. Finally, we thank D. Nykamp for providing programs and G. Buzsáki, L. Wittner, G. Ascoli, and D. Ropireddy for sharing CA3 pyramidal neuron models. Supported by the Fond zur Förderung der Wissenschaftlichen Forschung (P 24909-B24 to P.J.), the European Union (European Research Council Advanced Grant 268548 to P.J.), and the Deutsche Forschungsgemeinschaft (FR 620/14-1 to M.F.). M.F. is Senior Research Professor of the Hertie Foundation. The authors declare no conflicts of interest. Original data and programs were stored in the scientific repository of the Institute of Science and Technology Austria and are available on request. #MaschineShop #PreclinicalFacility #SelectionJonas
Open access: yes (repository)