Abstract
The permeability of the squid axon membrane was determined by the use of radioisotopes of Na, K, Ca, Cs, and Br. Effluxes of these isotopes were measured mainly by the method of intracellular injection. Measurements of influxes were carried out under continuous intracellular perfusion with an isotonic solution of potassium sulfate. The Na permeability of the resting (excitable) axonal membrane was found to be roughly equal to the K permeability. The permeability to anion was far smaller than that to cations. It is emphasized that the axonal membrane has properties of a cation exchanger. The physicochemical nature of the "two stable states" of the excitable membrane is discussed on the basis of ion exchange isotherms.
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Selected References
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- BAKER P. F., HODGKIN A. L., SHAW T. I. Replacement of the protoplasm of a giant nerve fibre with artificial solutions. Nature. 1961 Jun 3;190:885–887. doi: 10.1038/190885a0. [DOI] [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]
- HODGKIN A. L., KEYNES R. D. Active transport of cations in giant axons from Sepia and Loligo. J Physiol. 1955 Apr 28;128(1):28–60. doi: 10.1113/jphysiol.1955.sp005290. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., KEYNES R. D. Experiments on the injection of substances into squid giant axons by means of a microsyringe. J Physiol. 1956 Mar 28;131(3):592–616. doi: 10.1113/jphysiol.1956.sp005485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOKETSU K., NISHI S. Effect of hydrazine on the excitable membrane in sodium-free media. J Physiol. 1960 Feb;150:440–450. doi: 10.1113/jphysiol.1960.sp006396. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OIKAWA T., SPYROPOULOS C. S., TASAKI I., TEORELL T. Methods for perfusing the giant axon of Loligo pealii. Acta Physiol Scand. 1961 Jun;52:195–196. doi: 10.1111/j.1748-1716.1961.tb02218.x. [DOI] [PubMed] [Google Scholar]
- OOMURA Y., OZAKI S., MAENO T. Electrical activity of a giant nerve cell under abnormal conditions. Nature. 1961 Sep 23;191:1265–1267. doi: 10.1038/1911265a0. [DOI] [PubMed] [Google Scholar]
- SHANES A. M., BERMAN M. D. Kinetics of ion movement in the squid giant axon. J Gen Physiol. 1955 Nov 20;39(2):279–300. doi: 10.1085/jgp.39.2.279. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TASAKI I., HAGIWAR A. S. Demonstration of two stable potential states in the squid giant axon under tetraethylammonium chloride. J Gen Physiol. 1957 Jul 20;40(6):859–885. doi: 10.1085/jgp.40.6.859. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TASAKI I., SPYROPOULOS C. S. Permeability of the squid axon membrane to several organic molecules. Am J Physiol. 1961 Sep;201:413–419. doi: 10.1152/ajplegacy.1961.201.3.413. [DOI] [PubMed] [Google Scholar]