Abstract
Single-channel currents were recorded with the cell-attached patch-clamp technique from small clusters (2-20 cells) of spontaneously beating 7-d embryo ventricle cells. Because the preparation was rhythmically active, the trans-patch potential varied with the action potential (AP). The total current through the patch membrane was the patch action current (AC). ACs and APs could be recorded simultaneously, with two electrodes, or sequentially with one electrode. Channel activity, which varied depending on the number and type of channels in the patch, was present during normal cell firing. This method can reveal the kinetics and magnitudes of the specific currents that contributed to the AP, under conditions that reflect not only the time and voltage dependence of the channels, but also environmental factors that may influence channel behavior during the AP.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barrett J. N., Magleby K. L., Pallotta B. S. Properties of single calcium-activated potassium channels in cultured rat muscle. J Physiol. 1982 Oct;331:211–230. doi: 10.1113/jphysiol.1982.sp014370. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Beeler G. W., Reuter H. Reconstruction of the action potential of ventricular myocardial fibres. J Physiol. 1977 Jun;268(1):177–210. doi: 10.1113/jphysiol.1977.sp011853. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clay J. R., DeFelice L. J., DeHaan R. L. Current noise parameters derived from voltage noise and impedance in embryonic heart cell aggregates. Biophys J. 1979 Nov;28(2):169–184. doi: 10.1016/S0006-3495(79)85169-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clay J. R., DeFelice L. J. Relationship between membrane excitability and single channel open-close kinetics. Biophys J. 1983 May;42(2):151–157. doi: 10.1016/S0006-3495(83)84381-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clay J. R., DeHaan R. L. Fluctuations in interbeat interval in rhythmic heart-cell clusters. Role of membrane voltage noise. Biophys J. 1979 Dec;28(3):377–389. doi: 10.1016/S0006-3495(79)85187-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Colquhoun D., Neher E., Reuter H., Stevens C. F. Inward current channels activated by intracellular Ca in cultured cardiac cells. Nature. 1981 Dec 24;294(5843):752–754. doi: 10.1038/294752a0. [DOI] [PubMed] [Google Scholar]
- Conti F., De Felice L. J., Wanke E. Potassium and sodium ion current noise in the membrane of the squid giant axon. J Physiol. 1975 Jun;248(1):45–82. doi: 10.1113/jphysiol.1975.sp010962. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conti F., Neher E. Single channel recordings of K+ currents in squid axons. Nature. 1980 May 15;285(5761):140–143. doi: 10.1038/285140a0. [DOI] [PubMed] [Google Scholar]
- DeHann R. L. Regulation of spontaneous activity and growth of embryonic chick heart cells in tissue culture. Dev Biol. 1967 Sep;16(3):216–249. doi: 10.1016/0012-1606(67)90025-5. [DOI] [PubMed] [Google Scholar]
- Fenwick E. M., Marty A., Neher E. A patch-clamp study of bovine chromaffin cells and of their sensitivity to acetylcholine. J Physiol. 1982 Oct;331:577–597. doi: 10.1113/jphysiol.1982.sp014393. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., HUXLEY A. F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
- Jackson M. B., Lecar H., Brenneman D. E., Fitzgerald S., Nelson P. G. Electrical development in spinal cord cell culture. J Neurosci. 1982 Aug;2(8):1052–1061. doi: 10.1523/JNEUROSCI.02-08-01052.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lux H. D., Neher E., Marty A. Single channel activity associated with the calcium dependent outward current in Helix pomatia. Pflugers Arch. 1981 Mar;389(3):293–295. doi: 10.1007/BF00584792. [DOI] [PubMed] [Google Scholar]
- McAllister R. E., Noble D., Tsien R. W. Reconstruction of the electrical activity of cardiac Purkinje fibres. J Physiol. 1975 Sep;251(1):1–59. doi: 10.1113/jphysiol.1975.sp011080. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mentrard D., Vassort G., Fischmeister R. Calcium-mediated inactivation of the calcium conductance in cesium-loaded frog heart cells. J Gen Physiol. 1984 Jan;83(1):105–131. doi: 10.1085/jgp.83.1.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nathan R. D., DeHaan R. L. Voltage clamp analysis of embryonic heart cell aggregates. J Gen Physiol. 1979 Feb;73(2):175–198. doi: 10.1085/jgp.73.2.175. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Neher E., Sakmann B. Single-channel currents recorded from membrane of denervated frog muscle fibres. Nature. 1976 Apr 29;260(5554):799–802. doi: 10.1038/260799a0. [DOI] [PubMed] [Google Scholar]
- Sigworth F. J., Neher E. Single Na+ channel currents observed in cultured rat muscle cells. Nature. 1980 Oct 2;287(5781):447–449. doi: 10.1038/287447a0. [DOI] [PubMed] [Google Scholar]
- Sigworth F. J. Sodium channels in nerve apparently have two conductance states. Nature. 1977 Nov 17;270(5634):265–267. doi: 10.1038/270265a0. [DOI] [PubMed] [Google Scholar]
- Yanagihara K., Noma A., Irisawa H. Reconstruction of sino-atrial node pacemaker potential based on the voltage clamp experiments. Jpn J Physiol. 1980;30(6):841–857. doi: 10.2170/jjphysiol.30.841. [DOI] [PubMed] [Google Scholar]