Sodium currents in dissociated bull-frog sympathetic neurones.
PDF (2.3M)
Journal: 1988/January - Journal of Physiology
ISSN: 0022-3751
PUBMED: 2445980
Abstract:
1. Sodium currents were recorded from the cell bodies of single dissociated sympathetic neurones of bull-frogs, using patch electrodes in the whole-cell configuration, in Cs+-loaded cells, using external Mn2+ to block calcium currents. 2. A discontinuous single-electrode voltage-clamp method was used. Switching frequencies of 40-50 kHz were possible with 0.5-2 M omega electrodes, giving clamp settling times of approximately 0.2 ms and adequate clamp of currents up to 30 nA. 3. The sodium currents required unusually positive voltages for both activation and inactivation, with half of the maximal observed conductance activating at +2 mV, and half-maximal steady-state inactivation at -35 mV. Both fast (in the order of milliseconds) and slow (in the order of seconds) inactivation processes occurred. 4. Two pharmacologically and kinetically distinct sodium currents were observed. The larger current was blocked by tetrodotoxin (TTX) and saxitoxin (STX) with I50 values (i.e. the concentration which results in 50% inhibition) of 10 nM or lower, and activated and inactivated relatively rapidly. 5. A smaller current (approximately 25% of peak current) was blocked by 0.1-1 microM-STX but not by 1-10 microM-TTX. It also activated rapidly, but inactivated approximately 3-fold more slowly than the larger current. The slower current was blocked 75-90% by Cd2+ (50-200 microM).
Open in
PUBMED | PMC | Google Scholar | Wikipedia
Relations:
Content
Citations
(40)
References
(47)
Chemicals
(4)
Organisms
(2)
Processes
(2)
Anatomy
(2)
Affiliates
(1)
Similar articles
Articles by the same authors
Discussion board
J Physiol 389: 605-627
PMID: 2445980

Sodium currents in dissociated bull-frog sympathetic neurones.

Abstract

1. Sodium currents were recorded from the cell bodies of single dissociated sympathetic neurones of bull-frogs, using patch electrodes in the whole-cell configuration, in Cs+-loaded cells, using external Mn2+ to block calcium currents. 2. A discontinuous single-electrode voltage-clamp method was used. Switching frequencies of 40-50 kHz were possible with 0.5-2 M omega electrodes, giving clamp settling times of approximately 0.2 ms and adequate clamp of currents up to 30 nA. 3. The sodium currents required unusually positive voltages for both activation and inactivation, with half of the maximal observed conductance activating at +2 mV, and half-maximal steady-state inactivation at -35 mV. Both fast (in the order of milliseconds) and slow (in the order of seconds) inactivation processes occurred. 4. Two pharmacologically and kinetically distinct sodium currents were observed. The larger current was blocked by tetrodotoxin (TTX) and saxitoxin (STX) with I50 values (i.e. the concentration which results in 50% inhibition) of 10 nM or lower, and activated and inactivated relatively rapidly. 5. A smaller current (approximately 25% of peak current) was blocked by 0.1-1 microM-STX but not by 1-10 microM-TTX. It also activated rapidly, but inactivated approximately 3-fold more slowly than the larger current. The slower current was blocked 75-90% by Cd2+ (50-200 microM).

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (2.3M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.
icon of scanned page 605
605
icon of scanned page 606
606
icon of scanned page 607
607
icon of scanned page 608
608
icon of scanned page 609
609
icon of scanned page 610
610
icon of scanned page 611
611
icon of scanned page 612
612
icon of scanned page 613
613
icon of scanned page 614
614
icon of scanned page 615
615
icon of scanned page 616
616
icon of scanned page 617
617
icon of scanned page 618
618
icon of scanned page 619
619
icon of scanned page 620
620
icon of scanned page 621
621
icon of scanned page 622
622
icon of scanned page 623
623
icon of scanned page 624
624
icon of scanned page 625
625
icon of scanned page 626
626
icon of scanned page 627
627

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Adams PR, Galvan M. Voltage-dependent currents of vertebrate neurons and their role in membrane excitability. Adv Neurol. 1986;44:137–170. [PubMed] [Google Scholar]
  • Adams PR, Brown DA, Constanti A. M-currents and other potassium currents in bullfrog sympathetic neurones. J Physiol. 1982 Sep;330:537–572.[PMC free article] [PubMed] [Google Scholar]
  • Adrian RH, Chandler WK, Hodgkin AL. Voltage clamp experiments in striated muscle fibres. J Physiol. 1970 Jul;208(3):607–644.[PMC free article] [PubMed] [Google Scholar]
  • Akaike N, Hattori K, Inomata N, Oomura Y. gamma-Aminobutyric-acid- and pentobarbitone-gated chloride currents in internally perfused frog sensory neurones. J Physiol. 1985 Mar;360:367–386.[PMC free article] [PubMed] [Google Scholar]
  • Aldrich RW, Corey DP, Stevens CF. A reinterpretation of mammalian sodium channel gating based on single channel recording. Nature. 1983 Dec 1;306(5942):436–441. [PubMed] [Google Scholar]
  • Arhem P. Effects of some heavy metal ions on the ionic currents of myelinated fibres from Xenopus laevis. J Physiol. 1980 Sep;306:219–231.[PMC free article] [PubMed] [Google Scholar]
  • Bader CR, Bernheim L, Bertrand D. Sodium-activated potassium current in cultured avian neurones. Nature. 1985 Oct 10;317(6037):540–542. [PubMed] [Google Scholar]
  • Bader CR, Bertrand D, Dupin E. Voltage-dependent potassium currents in developing neurones from quail mesencephalic neural crest. J Physiol. 1985 Sep;366:129–151.[PMC free article] [PubMed] [Google Scholar]
  • Barrett JN, Crill WE. Voltage clamp of cat motoneurone somata: properties of the fast inward current. J Physiol. 1980 Jul;304:231–249.[PMC free article] [PubMed] [Google Scholar]
  • Benoit E, Corbier A, Dubois JM. Evidence for two transient sodium currents in the frog node of Ranvier. J Physiol. 1985 Apr;361:339–360.[PMC free article] [PubMed] [Google Scholar]
  • Bossu JL, Feltz A. Patch-clamp study of the tetrodotoxin-resistant sodium current in group C sensory neurones. Neurosci Lett. 1984 Oct 12;51(2):241–246. [PubMed] [Google Scholar]
  • Bowers CW. A cadmium-sensitive, tetrodotoxin-resistant sodium channel in bullfrog autonomic axons. Brain Res. 1985 Aug 5;340(1):143–147. [PubMed] [Google Scholar]
  • Brismar T. Slow mechanism for sodium permeability inactivation in myelinated nerve fibre of Xenopus laevis. J Physiol. 1977 Sep;270(2):283–297.[PMC free article] [PubMed] [Google Scholar]
  • Brown AM, Lee KS, Powell T. Sodium current in single rat heart muscle cells. J Physiol. 1981 Sep;318:479–500.[PMC free article] [PubMed] [Google Scholar]
  • Cohen IS, Datyner NB, Gintant GA, Mulrine NK, Pennefather P. A note on the relation of maximum upstroke velocity to peak inward current recorded by the voltage clamp. Circ Res. 1985 Sep;57(3):482–484. [PubMed] [Google Scholar]
  • COOMBS JS, CURTIS DR, ECCLES JC. The generation of impulses in motoneurones. J Physiol. 1957 Dec 3;139(2):232–249.[PMC free article] [PubMed] [Google Scholar]
  • DiFrancesco D, Ferroni A, Visentin S, Zaza A. Cadmium-induced blockade of the cardiac fast Na channels in calf Purkinje fibres. Proc R Soc Lond B Biol Sci. 1985 Feb 22;223(1233):475–484. [PubMed] [Google Scholar]
  • Fenwick EM, Marty A, Neher E. Sodium and calcium channels in bovine chromaffin cells. J Physiol. 1982 Oct;331:599–635.[PMC free article] [PubMed] [Google Scholar]
  • Fernandez JM, Fox AP, Krasne S. Membrane patches and whole-cell membranes: a comparison of electrical properties in rat clonal pituitary (GH3) cells. J Physiol. 1984 Nov;356:565–585.[PMC free article] [PubMed] [Google Scholar]
  • Finkel AS, Redman S. Theory and operation of a single microelectrode voltage clamp. J Neurosci Methods. 1984 Jun;11(2):101–127. [PubMed] [Google Scholar]
  • Fox JM. Ultra-slow inactivation of the ionic currents through the membrane of myelinated nerve. Biochim Biophys Acta. 1976 Mar 5;426(2):232–244. [PubMed] [Google Scholar]
  • FRANKENHAEUSER B, HUXLEY AF. THE ACTION POTENTIAL IN THE MYELINATED NERVE FIBER OF XENOPUS LAEVIS AS COMPUTED ON THE BASIS OF VOLTAGE CLAMP DATA. J Physiol. 1964 Jun;171:302–315.[PMC free article] [PubMed] [Google Scholar]
  • Frelin C, Cognard C, Vigne P, Lazdunski M. Tetrodotoxin-sensitive and tetrodotoxin-resistant Na+ channels differ in their sensitivity to Cd2+ and Zn2+. Eur J Pharmacol. 1986 Mar 18;122(2):245–250. [PubMed] [Google Scholar]
  • Geduldig D, Gruener R. Voltage clamp of the Aplysia giant neurone: early sodium and calcium currents. J Physiol. 1970 Nov;211(1):217–244.[PMC free article] [PubMed] [Google Scholar]
  • Gonoi T, Hille B, Catterall WA. Voltage clamp analysis of sodium channels in normal and scorpion toxin-resistant neuroblastoma cells. J Neurosci. 1984 Nov;4(11):2836–2842.[PMC free article] [PubMed] [Google Scholar]
  • Gonoi T, Sherman SJ, Catterall WA. Voltage clamp analysis of tetrodotoxin-sensitive and -insensitive sodium channels in rat muscle cells developing in vitro. J Neurosci. 1985 Sep;5(9):2559–2564.[PMC free article] [PubMed] [Google Scholar]
  • Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. [PubMed] [Google Scholar]
  • Harris JB, Thesleff S. Studies on tetrodotoxin resistant action potentials in denervated skeletal muscle. Acta Physiol Scand. 1971 Nov;83(3):382–388. [PubMed] [Google Scholar]
  • Hess P, Tsien RW. Mechanism of ion permeation through calcium channels. Nature. 309(5967):453–456. [PubMed] [Google Scholar]
  • Hille B, Woodhull AM, Shapiro BI. Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH. Philos Trans R Soc Lond B Biol Sci. 1975 Jun 10;270(908):301–318. [PubMed] [Google Scholar]
  • HODGKIN AL, HUXLEY AF. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544.[PMC free article] [PubMed] [Google Scholar]
  • Ikeda SR, Schofield GG, Weight FF. Na+ and Ca2+ currents of acutely isolated adult rat nodose ganglion cells. J Neurophysiol. 1986 Mar;55(3):527–539. [PubMed] [Google Scholar]
  • Ishizuka S, Hattori K, Akaike N. Separation of ionic currents in the somatic membrane of frog sensory neurons. J Membr Biol. 1984;78(1):19–28. [PubMed] [Google Scholar]
  • Jones SW. Muscarinic and peptidergic excitation of bull-frog sympathetic neurones. J Physiol. 1985 Sep;366:63–87.[PMC free article] [PubMed] [Google Scholar]
  • Kleinhaus AL, Prichard JW. Sodium dependent tetrodotoxin-resistant action potentials in a leech neuron. Brain Res. 1976 Feb 6;102(2):368–373. [PubMed] [Google Scholar]
  • Kostyuk PG, Veselovsky NS, Tsyndrenko AY. Ionic currents in the somatic membrane of rat dorsal root ganglion neurons-I. Sodium currents. Neuroscience. 1981;6(12):2423–2430. [PubMed] [Google Scholar]
  • Kuffler SW, Sejnowski TJ. Peptidergic and muscarinic excitation at amphibian sympathetic synapses. J Physiol. 1983 Aug;341:257–278.[PMC free article] [PubMed] [Google Scholar]
  • Lee KS, Akaike N, Brown AM. Trypsin inhibits the action of tetrodotoxin on neurones. Nature. 1977 Feb 24;265(5596):751–753. [PubMed] [Google Scholar]
  • Mayer ML. A calcium-activated chloride current generates the after-depolarization of rat sensory neurones in culture. J Physiol. 1985 Jul;364:217–239.[PMC free article] [PubMed] [Google Scholar]
  • NISHI S, KOKETSU K. Electrical properties and activities of single sympathetic neurons in frogs. J Cell Comp Physiol. 1960 Feb;55:15–30. [PubMed] [Google Scholar]
  • Noda M, Ikeda T, Kayano T, Suzuki H, Takeshima H, Kurasaki M, Takahashi H, Numa S. Existence of distinct sodium channel messenger RNAs in rat brain. Nature. 1986 Mar 13;320(6058):188–192. [PubMed] [Google Scholar]
  • Nowycky MC, Fox AP, Tsien RW. Three types of neuronal calcium channel with different calcium agonist sensitivity. Nature. 1985 Aug 1;316(6027):440–443. [PubMed] [Google Scholar]
  • Pappone PA. Voltage-clamp experiments in normal and denervated mammalian skeletal muscle fibres. J Physiol. 1980 Sep;306:377–410.[PMC free article] [PubMed] [Google Scholar]
  • Vandenberg CA, Horn R. Inactivation viewed through single sodium channels. J Gen Physiol. 1984 Oct;84(4):535–564.[PMC free article] [PubMed] [Google Scholar]
  • Weiss RE, Horn R. Functional differences between two classes of sodium channels in developing rat skeletal muscle. Science. 1986 Jul 18;233(4761):361–364. [PubMed] [Google Scholar]
  • Wilson WA, Goldner MM. Voltage clamping with a single microelectrode. J Neurobiol. 1975 Jul;6(4):411–422. [PubMed] [Google Scholar]
  • Wollner DA, Catterall WA. Antigenic differences among the voltage-sensitive sodium channels in the peripheral and central nervous systems and skeletal muscle. Brain Res. 1985 Apr 1;331(1):145–149. [PubMed] [Google Scholar]
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794.
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794.
Copyright notice
Abstract
1. Sodium currents were recorded from the cell bodies of single dissociated sympathetic neurones of bull-frogs, using patch electrodes in the whole-cell configuration, in Cs+-loaded cells, using external Mn2+ to block calcium currents. 2. A discontinuous single-electrode voltage-clamp method was used. Switching frequencies of 40-50 kHz were possible with 0.5-2 M omega electrodes, giving clamp settling times of approximately 0.2 ms and adequate clamp of currents up to 30 nA. 3. The sodium currents required unusually positive voltages for both activation and inactivation, with half of the maximal observed conductance activating at +2 mV, and half-maximal steady-state inactivation at -35 mV. Both fast (in the order of milliseconds) and slow (in the order of seconds) inactivation processes occurred. 4. Two pharmacologically and kinetically distinct sodium currents were observed. The larger current was blocked by tetrodotoxin (TTX) and saxitoxin (STX) with I50 values (i.e. the concentration which results in 50% inhibition) of 10 nM or lower, and activated and inactivated relatively rapidly. 5. A smaller current (approximately 25% of peak current) was blocked by 0.1-1 microM-STX but not by 1-10 microM-TTX. It also activated rapidly, but inactivated approximately 3-fold more slowly than the larger current. The slower current was blocked 75-90% by Cd2+ (50-200 microM).
Collaboration tool especially designed for Life Science professionals.Drag-and-drop any entity to your messages.