PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jgenphysiolHomeThe Rockefeller University PressEditorsContactInstructions for AuthorsThis issue
 
J Gen Physiol. 1988 March 1; 91(3): 373–398.
PMCID: PMC2216136

The sodium current underlying action potentials in guinea pig hippocampal CA1 neurons

Abstract

Neurons were acutely dissociated from the CA1 region of hippocampal slices from guinea pigs. Whole-cell recording techniques were used to record and control membrane potential. When the electrode contained KF, the average resting potential was about -40 mV and action potentials in cells at -80 mV (current-clamped) had an amplitude greater than 100 mV. Cells were voltage-clamped at 22-24 degrees C with electrodes containing CsF. Inward currents generated with depolarizing voltage pulses reversed close to the sodium equilibrium potential and could be completely blocked with tetrodotoxin (1 microM). The amplitude of these sodium currents was maximal at about -20 mV and the amplitude of the tail currents was linear with potential, which indicates that the channels were ohmic. The sodium conductance increased with depolarization in a range from -60 to 0 mV with an average half-maximum at about -40 mV. The decay of the currents was not exponential at potentials more positive than -20 mV. The time to peak and half-decay time of the currents varied with potential and temperature. Half of the channels were inactivated at a potential of -75 mV and inactivation was essentially complete at -40 to -30 mV. Recovery from inactivation was not exponential and the rate varied with potential. At lower temperatures, the amplitude of sodium currents decreased, their time course became longer, and half-maximal inactivation shifted to more negative potentials. In a small fraction of cells studied, sodium currents were much more rapid but the voltage dependence of activation and inactivation was very similar.

Full Text

The Full Text of this article is available as a PDF (1.2M).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Adams DJ, Oxford GS. Interaction of internal anions with potassium channels of the squid giant axon. J Gen Physiol. 1983 Oct;82(4):429–448. [PMC free article] [PubMed]
  • Adrian RH, Chandler WK, Hodgkin AL. Slow changes in potassium permeability in skeletal muscle. J Physiol. 1970 Jul;208(3):645–668. [PubMed]
  • Barrett JN, Crill WE. Voltage clamp of cat motoneurone somata: properties of the fast inward current. J Physiol. 1980 Jul;304:231–249. [PubMed]
  • Belluzzi O, Sacchi O. A quantitative description of the sodium current in the rat sympathetic neurone. J Physiol. 1986 Nov;380:275–291. [PubMed]
  • Bevan S, Chiu SY, Gray PT, Ritchie JM. The presence of voltage-gated sodium, potassium and chloride channels in rat cultured astrocytes. Proc R Soc Lond B Biol Sci. 1985 Sep 23;225(1240):299–313. [PubMed]
  • Brown AM, Lee KS, Powell T. Sodium current in single rat heart muscle cells. J Physiol. 1981 Sep;318:479–500. [PubMed]
  • Brown DA, Griffith WH. Persistent slow inward calcium current in voltage-clamped hippocampal neurones of the guinea-pig. J Physiol. 1983 Apr;337:303–320. [PubMed]
  • Brown TH, Fricke RA, Perkel DH. Passive electrical constants in three classes of hippocampal neurons. J Neurophysiol. 1981 Oct;46(4):812–827. [PubMed]
  • Chiu SY. Inactivation of sodium channels: second order kinetics in myelinated nerve. J Physiol. 1977 Dec;273(3):573–596. [PubMed]
  • Chiu SY, Mrose HE, Ritchie JM. Anomalous temperature dependence of the sodium conductance in rabbit nerve compared with frog nerve. Nature. 1979 May 24;279(5711):327–328. [PubMed]
  • Chiu SY, Ritchie JM, Rogart RB, Stagg D. A quantitative description of membrane currents in rabbit myelinated nerve. J Physiol. 1979 Jul;292:149–166. [PubMed]
  • Dubinsky JM, Oxford GS. Ionic currents in two strains of rat anterior pituitary tumor cells. J Gen Physiol. 1984 Mar;83(3):309–339. [PMC free article] [PubMed]
  • FATT P. Sequence of events in synaptic activation of a motoneurone. J Neurophysiol. 1957 Jan;20(1):61–80. [PubMed]
  • Fenwick EM, Marty A, Neher E. Sodium and calcium channels in bovine chromaffin cells. J Physiol. 1982 Oct;331:599–635. [PubMed]
  • 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. [PubMed]
  • Finkel AS, Redman S. Theory and operation of a single microelectrode voltage clamp. J Neurosci Methods. 1984 Jun;11(2):101–127. [PubMed]
  • French CR, Gage PW. A threshold sodium current in pyramidal cells in rat hippocampus. Neurosci Lett. 1985 May 23;56(3):289–293. [PubMed]
  • Gray R, Johnston D. Rectification of single GABA-gated chloride channels in adult hippocampal neurons. J Neurophysiol. 1985 Jul;54(1):134–142. [PubMed]
  • Gundersen CB, Miledi R, Parker I. Voltage-operated channels induced by foreign messenger RNA in Xenopus oocytes. Proc R Soc Lond B Biol Sci. 1983 Nov 22;220(1218):131–140. [PubMed]
  • 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]
  • HODGKIN AL, HUXLEY AF. The components of membrane conductance in the giant axon of Loligo. J Physiol. 1952 Apr;116(4):473–496. [PubMed]
  • HODGKIN AL, HUXLEY AF. The dual effect of membrane potential on sodium conductance in the giant axon of Loligo. J Physiol. 1952 Apr;116(4):497–506. [PubMed]
  • Hodgkin AL, Nakajima S. The effect of diameter on the electrical constants of frog skeletal muscle fibres. J Physiol. 1972 Feb;221(1):105–120. [PubMed]
  • Huguenard JR, Alger BE. Whole-cell voltage-clamp study of the fading of GABA-activated currents in acutely dissociated hippocampal neurons. J Neurophysiol. 1986 Jul;56(1):1–18. [PubMed]
  • Iansek R, Redman SJ. An analysis of the cable properties of spinal motoneurones using a brief intracellular current pulse. J Physiol. 1973 Nov;234(3):613–636. [PubMed]
  • 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]
  • Jahnsen H. Extracellular activation and membrane conductances of neurones in the guinea-pig deep cerebellar nuclei in vitro. J Physiol. 1986 Mar;372:149–168. [PubMed]
  • Johnston D, Brown TH. Interpretation of voltage-clamp measurements in hippocampal neurons. J Neurophysiol. 1983 Aug;50(2):464–486. [PubMed]
  • Johnston D, Hablitz JJ, Wilson WA. Voltage clamp discloses slow inward current in hippocampal burst-firing neurones. Nature. 1980 Jul 24;286(5771):391–393. [PubMed]
  • Kay AR, Miles R, Wong RK. Intracellular fluoride alters the kinetic properties of calcium currents facilitating the investigation of synaptic events in hippocampal neurons. J Neurosci. 1986 Oct;6(10):2915–2920. [PubMed]
  • Kay AR, Wong RK. Isolation of neurons suitable for patch-clamping from adult mammalian central nervous systems. J Neurosci Methods. 1986 May;16(3):227–238. [PubMed]
  • Kostyuk PG. Intracellular perfusion of nerve cells and its effects on membrane currents. Physiol Rev. 1984 Apr;64(2):435–454. [PubMed]
  • 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]
  • Llinás R, Sugimori M. Electrophysiological properties of in vitro Purkinje cell somata in mammalian cerebellar slices. J Physiol. 1980 Aug;305:171–195. [PubMed]
  • Matteson DR, Armstrong CM. Na and Ca channels in a transformed line of anterior pituitary cells. J Gen Physiol. 1984 Mar;83(3):371–394. [PMC free article] [PubMed]
  • McCormick DA, Connors BW, Lighthall JW, Prince DA. Comparative electrophysiology of pyramidal and sparsely spiny stellate neurons of the neocortex. J Neurophysiol. 1985 Oct;54(4):782–806. [PubMed]
  • Moolenaar WH, Spector I. Ionic currents in cultured mouse neuroblastoma cells under voltage-clamp conditions. J Physiol. 1978 May;278:265–286. [PubMed]
  • Neumcke B, Stämpfli R. Sodium currents and sodium-current fluctuations in rat myelinated nerve fibres. J Physiol. 1982 Aug;329:163–184. [PubMed]
  • 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]
  • Numann RE, Wong RK. Voltage-clamp study on GABA response desensitization in single pyramidal cells dissociated from the hippocampus of adult guinea pigs. Neurosci Lett. 1984 Jun 29;47(3):289–294. [PubMed]
  • Schwartzkroin PA, Mathers LH. Physiological and morphological identification of a nonpyramidal hippocampal cell type. Brain Res. 1978 Nov 17;157(1):1–10. [PubMed]
  • Schwarz JR. The effect of temperature on Na currents in rat myelinated nerve fibres. Pflugers Arch. 1986 Apr;406(4):397–404. [PubMed]
  • Sigworth FJ, Neher E. Single Na+ channel currents observed in cultured rat muscle cells. Nature. 1980 Oct 2;287(5781):447–449. [PubMed]
  • Stafstrom CE, Schwindt PC, Crill WE. Repetitive firing in layer V neurons from cat neocortex in vitro. J Neurophysiol. 1984 Aug;52(2):264–277. [PubMed]
  • Stühmer W, Methfessel C, Sakmann B, Noda M, Numa S. Patch clamp characterization of sodium channels expressed from rat brain cDNA. Eur Biophys J. 1987;14(3):131–138. [PubMed]
  • Turner DA. Segmental cable evaluation of somatic transients in hippocampal neurons (CA1, CA3, and dentate). Biophys J. 1984 Jul;46(1):73–84. [PubMed]
  • Turner DA, Schwartzkroin PA. Steady-state electrotonic analysis of intracellularly stained hippocampal neurons. J Neurophysiol. 1980 Jul;44(1):184–199. [PubMed]
  • Vandenberg CA, Horn R. Inactivation viewed through single sodium channels. J Gen Physiol. 1984 Oct;84(4):535–564. [PMC free article] [PubMed]

Articles from The Journal of General Physiology are provided here courtesy of The Rockefeller University Press