Optimal estimation of ion-channel kinetics from macroscopic currents

PLoS One. 2012;7(4):e35208. doi: 10.1371/journal.pone.0035208. Epub 2012 Apr 20.

Abstract

Markov modeling provides an effective approach for modeling ion channel kinetics. There are several search algorithms for global fitting of macroscopic or single-channel currents across different experimental conditions. Here we present a particle swarm optimization(PSO)-based approach which, when used in combination with golden section search (GSS), can fit macroscopic voltage responses with a high degree of accuracy (errors within 1%) and reasonable amount of calculation time (less than 10 hours for 20 free parameters) on a desktop computer. We also describe a method for initial value estimation of the model parameters, which appears to favor identification of global optimum and can further reduce the computational cost. The PSO-GSS algorithm is applicable for kinetic models of arbitrary topology and size and compatible with common stimulation protocols, which provides a convenient approach for establishing kinetic models at the macroscopic level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Allosteric Regulation
  • Animals
  • Computer Simulation*
  • Kinetics
  • Large-Conductance Calcium-Activated Potassium Channels / chemistry*
  • Large-Conductance Calcium-Activated Potassium Channels / metabolism
  • Large-Conductance Calcium-Activated Potassium Channels / physiology
  • Markov Chains
  • Membrane Potentials
  • Models, Molecular*
  • Oocytes / metabolism
  • Patch-Clamp Techniques
  • Xenopus

Substances

  • Large-Conductance Calcium-Activated Potassium Channels