Abstract
We have recorded membrane impedance and voltage noise in the pacemaker range of potentials (-70 to -59 mV) from spheroidal aggregates of 7-d embryonic chick ventricle cells made quiescent by exposure to tetrodotoxin in medium containing 4.5 mM K+. The input capacitance is proportional to aggregate volume and therefore to total membrane area. The specific membrane capacitance is 1.24 microF/cm2. The input resistance at constant potential is inversely proportional to aggregate volume and therefore to total membrane area. The specific membrane resistance in 18 k omega . cm2 at -70 mV and increases to 81 k omega . cm2 at -59 mV. The RC time constant is 22 ms at -70 mV and increases to 146 ms at -59 mV. The aggregate transmembrane small-signal impedance can be represented by a parallel RC circuit itself in parallel with an inductive branch consisting of a resistor (rL) and an inductor (L) in series. The time constant of the inductive branch (L/rL) is 340 ms, and is only weakly dependent on potential. Correlation functions of aggregate voltage noise and the impedance data were modeled by a population of channels with simple open-close kinetics. The time constant of a channel (tau s) derived from the noise analysis is 300 ms. The low frequency limit of the pacemaker current noise (SI[0]), derived from the voltage noise and impedance, increases from 10(-20) A2/Hz . cm2 at -67 mV to 10(-19) A2/Hz . cm2 at -61 mV.
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Selected References
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- 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., Hille B., Neumcke B., Nonner W., Stämpfli R. Measurement of the conductance of the sodium channel from current fluctuations at the node of Ranvier. J Physiol. 1976 Nov;262(3):699–727. doi: 10.1113/jphysiol.1976.sp011616. [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]
- DeHaan R. L., Sachs H. G. Cell coupling in developing systems: the heart-cell paradigm. Curr Top Dev Biol. 1972;7:193–228. doi: 10.1016/s0070-2153(08)60072-1. [DOI] [PubMed] [Google Scholar]
- DeHaan R. L. The potassium-sensitivity of isolated embryonic heart cells increases with development. Dev Biol. 1970 Oct;23(2):226–240. doi: 10.1016/0012-1606(70)90096-5. [DOI] [PubMed] [Google Scholar]
- Dehaan R. L., Fozzard H. A. Membrane response to current pulses in spheroidal aggregates of embryonic heart cells. J Gen Physiol. 1975 Feb;65(2):207–222. doi: 10.1085/jgp.65.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg R. S., Barcilon V., Mathias R. T. Electrical properties of spherical syncytia. Biophys J. 1979 Jan;25(1):151–180. doi: 10.1016/S0006-3495(79)85283-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg R. S., Engel E. The spatial variation of membrane potential near a small source of current in a spherical cell. J Gen Physiol. 1970 Jun;55(6):736–757. doi: 10.1085/jgp.55.6.736. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg R. S., Rae J. L. Current-voltage relationships in the crystalline lens. J Physiol. 1976 Nov;262(2):285–300. doi: 10.1113/jphysiol.1976.sp011596. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Elsas L. J., Wheeler F. B., Danner D. J., DeHaan R. L. Amino acid transport by aggregates of cultured chicken heart cells. Effect of insulin. J Biol Chem. 1975 Dec 25;250(24):9381–9390. [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]
- Hill T. L., Chen Y. D. On the theory of ion transport across the nerve membrane. IV. Noise from the open-close kinetics of K + channels. Biophys J. 1972 Aug;12(8):948–959. doi: 10.1016/S0006-3495(72)86136-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MOSCONA A. Rotation-mediated histogenetic aggregation of dissociated cells. A quantifiable approach to cell interactions in vitro. Exp Cell Res. 1961 Jan;22:455–475. doi: 10.1016/0014-4827(61)90122-7. [DOI] [PubMed] [Google Scholar]
- Mauro A., Conti F., Dodge F., Schor R. Subthreshold behavior and phenomenological impedance of the squid giant axon. J Gen Physiol. 1970 Apr;55(4):497–523. doi: 10.1085/jgp.55.4.497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McAllister R. E., Noble D. The time and voltage dependence of the slow outward current in cardiac Purkinje fibres. J Physiol. 1966 Oct;186(3):632–662. doi: 10.1113/jphysiol.1966.sp008060. [DOI] [PMC free article] [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]
- McDonald T. F., DeHaan R. L. Ion levels and membrane potential in chick heart tissue and cultured cells. J Gen Physiol. 1973 Jan;61(1):89–109. doi: 10.1085/jgp.61.1.89. [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., 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]
- Noble D., Tsien R. W. The kinetics and rectifier properties of the slow potassium current in cardiac Purkinje fibres. J Physiol. 1968 Mar;195(1):185–214. doi: 10.1113/jphysiol.1968.sp008454. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sachs F. Electrophysiological properties of tissue cultured heart cells grown in a linear array. J Membr Biol. 1976 Sep 17;28(4):373–399. doi: 10.1007/BF01869706. [DOI] [PubMed] [Google Scholar]
- Sachs H. G., DeHaan R. L. Embryonic myocardial cell aggregates: volume and pulsation rate. Dev Biol. 1973 Jan;30(1):233–240. doi: 10.1016/0012-1606(73)90064-x. [DOI] [PubMed] [Google Scholar]
- Santora A. C., 2nd, Wheeler F. B., DeHaan R. L., Elsas L. J., 2nd Relationship of insulin binding to amino acid transport by cultured 14-day embryonic chick heart cells. Endocrinology. 1979 Apr;104(4):1059–1068. doi: 10.1210/endo-104-4-1059. [DOI] [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]
- Wanke E., DeFelice L. J., Conti F. Voltage noise, current noise and impedance in space clamped squid giant axon. Pflugers Arch. 1974 Feb 18;347(1):63–74. doi: 10.1007/BF00587055. [DOI] [PubMed] [Google Scholar]
