Abstract
The development of single channel recordings has brought with it the need to analyse enormous amounts of data. The data analysis is time consuming and subject to observer biases since the events are random in time and are contaminated with uncorrelated noise. We have developed a heuristic pattern recognition program which identifies with high precision single channel currents and rejects contaminating noise. The program interactively provides for a variety of amplitude and duration measures. Analysis is flexible and rapid: a file containing over 10,000 events can be analysed in under 2 h.
Specific detection features include variable lowpass filtering, automatic baseline restoration, and adaptive amplitude thresholds. A record is analysed through duration histograms, binomial estimates of the number of active channels present, cross-correlation estimates between parameters, spectral analysis of events and background noise, and stationarity of mean channel current. The graphic output facilities can plot raw data (after filtering and baseline restoration) with the idealized signal superimposed or with detected events underlined. A batch processing facility has been included to allow processing of data during periods of low computer demand.
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References
Colquhoun D, Hawkes AG (1981) On the stochastic properties of single ion channels. Proc Roy Soc B 211:205–235
Colquhoun D, Hawkes AG (1977) Relaxation and fluctuations of membrane currents that flow through drug-operated channels. Proc Roy Soc 199:231–262
Elson HF (1979) A possible modulation of acctylcholine receptors of embryonic chick muscle cells by α-bungarotoxin. J Supramol Struct 10:39–50
Hamill OP, Marty A, Neher E, Sakmann B, Sigworth F (1981) Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflügers Arch 391 (2):85–100
Korn H, Triller A, Mallet A, Faber DS (1981) Fluctuating responses at a central synapse:n of binomial fit predicts number of stained presynaptic boutons. Science 213:898–901
Marquardt DW (1964) Least squares estimation of nonlinear parameters. IBM Share Library 3094:15–20
Neher E (1981) Unit conductance studies in biological membranes. In: Baker PF (ed) Techniques in cellular physiology. Elsevier/North Holland, Amsterdam, pp P121/1-P121/16
Neher E, Sakmann B (1976) Single channel currents recorded from membrane of denervated frog muscle fibers. Nature 260:799–802
Neher E, Steinbach JH (1978) Local anesthetics transiently block currents through single acetylcholine receptor channels. J Physiol (Lond) 277:153–176
Nelson D, Sachs F (1979) Single ionic channel observed in tissue cultured muscle. Nature 282:861–863
Nelson D, Sachs F (1981) Ethanol decreases dissociation of agonist from nicotinic channels. Biophys J 33:121a
Nelson D, Sachs F (1982) Agonist and channel kinetics of the nicotinic acetylcholine receptor. Biophys J 37 (2):321a
Ostrem J, Falconer D (1981) A differential operator technique for restoring degraded signals and images. IEEE trans. Pattern Anal Mach Intell PAMI 3 (3):278–284
Patlak J, Horn R (1982) The effect ofn-bromoacetamide on single sodium channel currents in excised membrane patches. J Gen Physiol 79(3):333–351
Peled A, Liu B (1974) Digital signal processing. Wiley and Sons, New York
Sachs F, Barkakati N (1980) The amplitude distribution of single channel currents can yield dose response information. Biophys Soc Abstr 2425:174
Sytkowski AJ, Vogel Z, Nirenberg M (1973) Development of acytylcholine receptor clusters on cultured muscle cells. Proc Nat Acad 70:270–274
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Sachs, F., Neil, J. & Barkakati, N. The automated analysis of data from single ionic channels. Pflugers Arch. 395, 331–340 (1982). https://doi.org/10.1007/BF00580798
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DOI: https://doi.org/10.1007/BF00580798