Systematic analysis of the contributions of stochastic voltage gated channels to neuronal noise.

Abstract

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Electrical signaling in neurons is mediated by the openingand closing of large numbers of individual ion channels. The ion channel'sstate transitions are stochastic and introduce fluctuations in themacroscopic current through ion channel populations. This createsan unavoidable source of intrinsic electrical noise for the neuron,leading to fluctuations in the membrane potential and spontaneousspikes. While this effect is well known, the impact of channel noiseon single neuron dynamics remains poorly understood. Most resultsare based on numerical simulations. There is no agreement, even intheoretical studies, on which ion channel type is the dominant noisesource, nor how inclusion of additional ion channel types affects voltagenoise. Here we describe a framework to calculate voltage noise directlyfrom an arbitrary set of ion channel models, and discuss how this canbe use to estimate spontaneous spike rates.

Keywords

• simulation
• Voltage-gated ion channels
• Hodgkin-Huxley
• Channel noise
• spontaneous firing