• Open Access

Intrinsic subthreshold oscillations extend the influence of inhibitory synaptic inputs on cortical pyramidal neurons

Authors

  • Klaus M. Stiefel,

    1. Howard Hughes Medical Institute, Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
    2. Theoretical and Experimental Neurobiology Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
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  • Jean-Marc Fellous,

    1. Howard Hughes Medical Institute, Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
    2. Department of Psychology and Applied Mathematics, University of Arizona, Tucson, AZ, USA
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  • Peter J. Thomas,

    1. Howard Hughes Medical Institute, Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
    2. Departments of Mathematics, Biology, and Cognitive Science, Case Western Reserve University, Cleveland, OH, USA
    3. Department of Neuroscience, Oberlin College, Oberlin, OH, USA
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  • Terrence J. Sejnowski

    1. Howard Hughes Medical Institute, Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
    2. Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
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Dr Klaus M. Stiefel, Theoretical and Experimental Neurobiology Unit, Okinawa Institute of Science and Technology, 12-22, Suzaki, Uruma, Okinawa 904-2234.
E-mail: stiefel@salk.edu

Abstract

Fast inhibitory synaptic inputs, which cause conductance changes that typically last for 10–100 ms, participate in the generation and maintenance of cortical rhythms. We show here that these fast events can have influences that outlast the duration of the synaptic potentials by interacting with subthreshold membrane potential oscillations. Inhibitory postsynaptic potentials (IPSPs) in cortical neurons in vitro shifted the oscillatory phase for several seconds. The phase shift caused by two IPSPs or two current pulses summed non-linearly. Cholinergic neuromodulation increased the power of the oscillations and decreased the magnitude of the phase shifts. These results show that the intrinsic conductances of cortical pyramidal neurons can carry information about inhibitory inputs and can extend the integration window for synaptic input.

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