Abstract
It is often desirable to characterize membrane current fluctuations from ionic channels under conditions in which the mean current and the variance of the fluctuations change with time. A simple theory is developed that relates the power spectrum to the channel characteristics under such nonstationary conditions, assuming that the mean current time-course has been removed from the fluctuation records. Strategies for removing the mean time-course are discussed, the spectra are calculated from simulated channel fluctuations for comparison with the theory.
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- Colquhoun D., Hawkes A. G. Relaxation and fluctuations of membrane currents that flow through drug-operated channels. Proc R Soc Lond B Biol Sci. 1977 Nov 14;199(1135):231–262. doi: 10.1098/rspb.1977.0137. [DOI] [PubMed] [Google Scholar]
- Conti F., Neumcke B., Nonner W., Stämpfli R. Conductance fluctuations from the inactivation process of sodium channels in myelinated nerve fibres. J Physiol. 1980 Nov;308:217–239. doi: 10.1113/jphysiol.1980.sp013469. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DeFelice L. J. Fluctuation analysis in neurobiology. Int Rev Neurobiol. 1977;20:169–208. doi: 10.1016/s0074-7742(08)60653-4. [DOI] [PubMed] [Google Scholar]
- Magleby K. L., Stevens C. F. A quantitative description of end-plate currents. J Physiol. 1972 May;223(1):173–197. doi: 10.1113/jphysiol.1972.sp009840. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neher E., Stevens C. F. Conductance fluctuations and ionic pores in membranes. Annu Rev Biophys Bioeng. 1977;6:345–381. doi: 10.1146/annurev.bb.06.060177.002021. [DOI] [PubMed] [Google Scholar]
- Sigworth F. J. Covariance of nonstationary sodium current fluctuations at the node of Ranvier. Biophys J. 1981 Apr;34(1):111–133. doi: 10.1016/S0006-3495(81)84840-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sigworth F. J. The variance of sodium current fluctuations at the node of Ranvier. J Physiol. 1980 Oct;307:97–129. doi: 10.1113/jphysiol.1980.sp013426. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stevens C. F. Inferences about membrane properties from electrical noise measurements. Biophys J. 1972 Aug;12(8):1028–1047. doi: 10.1016/S0006-3495(72)86141-1. [DOI] [PMC free article] [PubMed] [Google Scholar]