MCMC for Ion-Channel Sojourn-Time Data: A Good Proposal.


Stochastic modeling of ion-channels has come a long way since the patchclamp technique enabled the current flowing through a single channel to be recorded. But a kinetic model is only as good as the reliability of its rate constants, and obtaining good estimates of parameter uncertainty remains challenging. The article by Epstein et al. (1) in this issue of the Biophysical Journal presents an exciting, new methodology for making inferences about such parameters. The gating mechanism of a single ion-channel is typically modeled as a finite-state continuous-time Markov chain, whose states are aggregated into two classes (either open or shut). The theory of such models of singleion channels was largely worked out ~30 years ago (e.g., Colquhoun and Hawkes (2) and Fredkin et al. (3)). Estimation of rate constants of a model from single-channel recordings is more problematic. The aggregation of states means that distinct models of channel gating can yield probabilistically indistinguishable observable processes. Another problem is that single-channel current recordings are corrupted by noise and low-pass filtering, and are sampled at finite intervals. The sequence of open and closed sojourns

DOI: 10.1016/j.bpj.2016.02.042

Cite this paper

@article{Ball2016MCMCFI, title={MCMC for Ion-Channel Sojourn-Time Data: A Good Proposal.}, author={Frank G Ball}, journal={Biophysical journal}, year={2016}, volume={111 2}, pages={267-268} }