PhaseResetting Analysis of GammaFrequency Synchr

Authors: Hugo Zeberg Nathan W Gouwens Kunichika Tsumoto Takashi Tateno Kazuyuki Aihara Hugh P C Robinson

Publish Date: 2012

Volume: , Issue: , Pages: 489-509

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Abstract

Synchronous firing of cortical fastspiking FS interneurons is important in generating gamma frequency 30–80 Hz oscillations These cells connect with each other both through inhibitory chemical synapses and through gap junctions To understand how these synaptic interactions control synchronization we injected artificial synaptic conductances in FS cells and measured the phase resetting produced by synaptic inputs the synaptic phaseresetting function SPRF during gammafrequency firing We found that artificial GABAA receptor and gap junctional conductances made distinct contributions to the SPRF which had a remarkably simple piecewise linear form with a sharp break between regions of phase delay and advance Analysing the SPRF shows how the intrinsic properties of FS neurons and their synaptic connections allow synchronization of firing over a wide gamma frequency band and upper and lower frequency limits of this band are shown to be controlled by gap junctions and GABAergic inhibition respectively This phaseresetting model gives insight into how FS cells synchronize so effectively at gamma oscillations and can be a building block in largescale simulations of the FS cell networks in order to understand the onset and stability of patterns of gamma oscillation in the cortexSupported by grants from the BBSRC EC and the Daiwa Foundation HPCR and a GrantinAid for Scientific Research on Priority Areas 17022012 from MEXT KA NWG was supported by a Churchill Foundation scholarship We thank Boris Gutkin for useful discussions

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