Distance-dependent inhibition facilitates focality of gamma oscillations in the dentate gyrus Journal Article

Author(s): Strüber, Michael; Sauer, Jonas-Frederic; Jonas, Peter; Bartos, Marlene
Article Title: Distance-dependent inhibition facilitates focality of gamma oscillations in the dentate gyrus
Affiliation IST Austria
Abstract: Gamma oscillations (30–150 Hz) in neuronal networks are associated with the processing and recall of information. We measured local field potentials in the dentate gyrus of freely moving mice and found that gamma activity occurs in bursts, which are highly heterogeneous in their spatial extensions, ranging from focal to global coherent events. Synaptic communication among perisomatic-inhibitory interneurons (PIIs) is thought to play an important role in the generation of hippocampal gamma patterns. However, how neuronal circuits can generate synchronous oscillations at different spatial scales is unknown. We analyzed paired recordings in dentate gyrus slices and show that synaptic signaling at interneuron-interneuron synapses is distance dependent. Synaptic strength declines whereas the duration of inhibitory signals increases with axonal distance among interconnected PIIs. Using neuronal network modeling, we show that distance-dependent inhibition generates multiple highly synchronous focal gamma bursts allowing the network to process complex inputs in parallel in flexibly organized neuronal centers.
Journal Title: Nature Communications
Volume: 8
ISSN: 2041-1723
Publisher: Nature Publishing Group  
Date Published: 2017-10-02
Start Page: Article number: 758
Copyright Statement: CC BY 4.0
DOI: 10.1038/s41467-017-00936-3
Notes: We thank Drs Imre Vida and Pepe Alcami for critically reading initial versions of the manuscript and Drs Ad Aertsen and Josef Bischofberger for fruitful discussions at earlier stages of the project. We thank Dr Patrick Ruther and Tobias Holzhammer for contributing silicon probes. This study was supported by grants from the Lichtenberg Award (Volkswagenstiftung; M.B.), the Schram Foundation (M.B.), the German Research Foundation (DFG BA 1582/2-1 and FOR2143, M.B.), the Excellence Initiative, GSC-4 Spemann Graduate School (M.S.), Brain-Links Brain-Tools, and the Cluster of Excellence EXC 1086 (M.B.). This project has received funding from the Fond zur Förderung der Wissenschaftlichen Forschung (P 24909-B24) and the European Research Council (ERC) under the European Union’s 7th framework program with grant agreement number 268548 (P.J.).
Open access: yes (OA journal)