Skip to main content
NCBI home page
Biophysical Journal logoLink to Biophysical Journal
. 1979 Apr;26(1):133–142. doi: 10.1016/S0006-3495(79)85240-6

Admittance change of squid axon during action potentials. Change in capacitive component due to sodium currents.

S Takashima
PMCID: PMC1328508  PMID: 262409

Abstract

Since the discovery of Cole and Curtis (1938. Nature (Lond.). 142:209 and 1939. J. Gen. Physiol. 22:649) that the imaginary components, i.e., capacitive and inductive components, of the admittance of squid axon membrane remained unchanged during the action potential, there have been numerous studies on impedance and admittance characteristics of nerves. First of all, it is now known that the dielectric capacitance of the membrane is frequency dependent. Second, the recent observation of gating currents indicates that dipolar molecules may be involved in the onset of ionic currents. Under these circumstances, the author felt it necessary to reinvestigate the membrane admittance characteristics of nerve axons. The measurements by Cole and Curtis were performed mainly at 20 kHz, indicating that their observation was limited only to the passive membrane capacitance. To detect the change in the capacitive component during the action potential, we performed transient admittance measurements at lower frequencies. However, the frequency range of the measurements was restricted because of the short duration of the normal action potential. In addition, a change in the inductive component obscured the low frequency behavior of the capacitance. To use wider frequency range and simplify the system by eliminating the inductive component, the potassium current was blocked by tetraethyl ammonium, and the increase in the capacitive component was reinvestigated during the long action potential. The admittance change under this condition was found to be mostly capacitive, and conductance change was very small. The increase in the capacitive component was from 1.0 to 1.23 muF/cm2.

Full text

PDF
133

Images in this article

137FIGURE 2
on p.137

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adrian R. H., Almers W. The voltage dependence of membrane capacity. J Physiol. 1976 Jan;254(2):317–338. doi: 10.1113/jphysiol.1976.sp011234. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Armstrong C. M., Bezanilla F. Charge movement associated with the opening and closing of the activation gates of the Na channels. J Gen Physiol. 1974 May;63(5):533–552. doi: 10.1085/jgp.63.5.533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Armstrong C. M., Bezanilla F. Currents related to movement of the gating particles of the sodium channels. Nature. 1973 Apr 13;242(5398):459–461. doi: 10.1038/242459a0. [DOI] [PubMed] [Google Scholar]
  4. Armstrong C. M. Currents associated with the ionic gating structures in nerve membrane. Ann N Y Acad Sci. 1975 Dec 30;264:265–277. doi: 10.1111/j.1749-6632.1975.tb31488.x. [DOI] [PubMed] [Google Scholar]
  5. Bezanilla F., Armstrong C. M. Gating currents of the sodium channels: three ways to block them. Science. 1974 Feb 22;183(4126):753–754. doi: 10.1126/science.183.4126.753. [DOI] [PubMed] [Google Scholar]
  6. CHANDLER W. K., FITZHUGH R., COLE K. S. Theoretical stability properties of a space-clamped axon. Biophys J. 1962 Mar;2:105–127. doi: 10.1016/s0006-3495(62)86844-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cole K. S., Curtis H. J. ELECTRIC IMPEDANCE OF THE SQUID GIANT AXON DURING ACTIVITY. J Gen Physiol. 1939 May 20;22(5):649–670. doi: 10.1085/jgp.22.5.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Cole K. S. Electrical properties of the squid axon sheath. Biophys J. 1976 Feb;16(2 Pt 1):137–142. doi: 10.1016/s0006-3495(76)85670-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cole K. S. Resistivity of axoplasm. I. Resistivity of extruded squid axoplasm. J Gen Physiol. 1975 Aug;66(2):133–138. doi: 10.1085/jgp.66.2.133. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Fishman H. M., Moore L. E., Poussart D. Asymmetry currents and admittance in squid axons. Biophys J. 1977 Aug;19(2):177–183. doi: 10.1016/S0006-3495(77)85578-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Fishman H. M., Poussart D. J., Moore L. E., Siebenga E. K+ conduction description from the low frequency impedance and admittance of squid axon. J Membr Biol. 1977 Apr 22;32(3-4):255–290. doi: 10.1007/BF01905222. [DOI] [PubMed] [Google Scholar]
  12. Guttman R., Feldman L. White noise measurement of squid axon membrane impedance. Biochem Biophys Res Commun. 1975 Nov 3;67(1):427–432. doi: 10.1016/0006-291x(75)90333-2. [DOI] [PubMed] [Google Scholar]
  13. 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]
  14. Keynes R. D., Rojas E. Kinetics and steady-state properties of the charged system controlling sodium conductance in the squid giant axon. J Physiol. 1974 Jun;239(2):393–434. doi: 10.1113/jphysiol.1974.sp010575. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Levitan E., Palti Y. Dipole moment, enthalpy, and entropy changes of Hodgkin-Huxley type kinetic units. Biophys J. 1975 Mar;15(3):239–251. doi: 10.1016/S0006-3495(75)85815-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. MAURO A. Anomalous impedance, a phenomenological property of time-variant resistance. An analytic review. Biophys J. 1961 Mar;1:353–372. doi: 10.1016/s0006-3495(61)86894-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Matsumoto N., Inoue I., Kishimoto U. The electric impedance of the squid axon membrane measured between internal and external electrodes. Jpn J Physiol. 1970 Oct 15;20(5):516–526. doi: 10.2170/jjphysiol.20.516. [DOI] [PubMed] [Google Scholar]
  18. Meves H. The effect of holding potential on the asymmetry currents in squid gaint axons. J Physiol. 1974 Dec;243(3):847–867. doi: 10.1113/jphysiol.1974.sp010780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Nonner W., Rojas E., Stämpfli H. Displacement currents in the node of Ranvier. Voltage and time dependence. Pflugers Arch. 1975;354(1):1–18. doi: 10.1007/BF00584499. [DOI] [PubMed] [Google Scholar]
  20. Takashima S. Frequency domain analysis of asymmetry current in squid axon membrane. Biophys J. 1978 Apr;22(1):115–119. doi: 10.1016/S0006-3495(78)85475-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Takashima S. Membrane capacity of squid giant axon during hyper- and depolarizations. J Membr Biol. 1976 Jun 9;27(1-2):21–39. doi: 10.1007/BF01869127. [DOI] [PubMed] [Google Scholar]
  22. Takashima S., Schwan H. P. Passive electrical properties of squid axon membrane. J Membr Biol. 1974;17(1):51–68. doi: 10.1007/BF01870172. [DOI] [PubMed] [Google Scholar]
  23. Takashima S., Yantorno R. Investigation of voltage-dependent membrane capacity of squid giant axons. Ann N Y Acad Sci. 1977 Dec 30;303:306–321. [PubMed] [Google Scholar]
  24. Takashima S., Yantorno R., Novack R. Dipole moment changes and voltage dependent membrane capacity of squid axon. Biochim Biophys Acta. 1977 Aug 15;469(1):74–88. doi: 10.1016/0005-2736(77)90327-3. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES