Theta-gamma-modulated synaptic currents in hippocampal granule cells in vivo define a mechanism for network oscillations Journal Article


Author(s): Pernía-Andrade, Alejandro; Jonas, Peter
Article Title: Theta-gamma-modulated synaptic currents in hippocampal granule cells in vivo define a mechanism for network oscillations
Affiliation IST Austria
Abstract: Theta-gamma network oscillations are thought to represent key reference signals for information processing in neuronal ensembles, but the underlying synaptic mechanisms remain unclear. To address this question, we performed whole-cell (WC) patch-clamp recordings from mature hippocampal granule cells (GCs) in vivo in the dentate gyrus of anesthetized and awake rats. GCs in vivo fired action potentials at low frequency, consistent with sparse coding in the dentate gyrus. GCs were exposed to barrages of fast AMPAR-mediated excitatory postsynaptic currents (EPSCs), primarily relayed from the entorhinal cortex, and inhibitory postsynaptic currents (IPSCs), presumably generated by local interneurons. EPSCs exhibited coherence with the field potential predominantly in the theta frequency band, whereas IPSCs showed coherence primarily in the gamma range. Action potentials in GCs were phase locked to network oscillations. Thus, theta-gamma-modulated synaptic currents may provide a framework for sparse temporal coding of information in the dentate gyrus.
Journal Title: Neuron
Volume: 81
Issue 1
ISSN: 0896-6273
Publisher: Elsevier  
Date Published: 2014-01-08
Start Page: 140
End Page: 152
Copyright Statement: CC-BY
Sponsor: This work was supported by the Fond zur Förderung der Wissenschaftlichen Forschung (P24909-B24) and the European Union (European Research Council Advanced Grant 268548 to P.J.).
URL:
DOI: 10.1016/j.neuron.2013.09.046
Notes: We thank Jozsef Csicsvari, José Guzmán, and John Lisman for critically reading prior versions of the manuscript. We also thank Michael Brecht and Albert Lee for generous introduction into in vivo patch-clamp techniques, T. Asenov for engineering mechanical devices, A. Schlögl for programming, F. Marr for technical assistance, and E. Kramberger for manuscript editing.
Open access: yes (OA journal)