Abstract
A new dissection procedure for preparing Myxicola giant axons for observation under voltage clamp is described. Preparation time is generally 40–45 min. 65–70% of the preparations attempted may be brought through the entire procedure, including insertion of the long internal electrode, and support an initial action potential amplitude of 100 mv or greater. Mean values for axon diameter, resting membrane potential, action potential amplitude, maximum peak inward transient current, and resting membrane resistance are 560 µ, —66.5 mv, 112 mv, 0.87 ma/cm2 and 1.22 KΩ cm 2 respectively. Cut branches do not seem to be a problem in this preparation. Behavior under voltage clamp is reasonably stable over several hours. Reductions in maximum inward transient current of 10% and in steady-state current of 5–10% are expected in the absence of any particular treatment. Tetrodotoxin blocks the action potential and both the inward and outward transient current, but has no effect on either the resting membrane potential or the steady-state current. This selective action of tetrodotoxin on the transient current is taken as an indication that this current component is probably carried by Na.
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Selected References
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- ARMSTRONG C. M., BINSTOCK L. THE EFFECTS OF SEVERAL ALCOHOLS ON THE PROPERTIES OF THE SQUID GIANT AXON. J Gen Physiol. 1964 Nov;48:265–277. doi: 10.1085/jgp.48.2.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blaustein M. P., Goldman D. E. Origin of axon membrane hyperpolarization under sucrose-gap. Biophys J. 2008 Dec 31;6(4):453–470. doi: 10.1016/S0006-3495(66)86669-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- COLE K. S., MOORE J. W. Liquid junction and membrane potentials of the squid giant axon. J Gen Physiol. 1960 May;43:971–980. doi: 10.1085/jgp.43.5.971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chandler W. K., Meves H. Voltage clamp experiments on internally perfused giant axons. J Physiol. 1965 Oct;180(4):788–820. doi: 10.1113/jphysiol.1965.sp007732. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldman L., Binstock L. Current separations in Myxicola giant axons. J Gen Physiol. 1969 Dec;54(6):741–754. doi: 10.1085/jgp.54.6.741. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldman L., Binstock L. Leak current rectification in Myxicola giant axons. Constant field and constant conductance components. J Gen Physiol. 1969 Dec;54(6):755–764. doi: 10.1085/jgp.54.6.755. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldman L. The effects of some ions on the membrane potential of the giant axon of Myxicola. J Cell Physiol. 1968 Feb;71(1):33–42. doi: 10.1002/jcp.1040710106. [DOI] [PubMed] [Google Scholar]
- HODGKIN A. L., HUXLEY A. F., KATZ B. Measurement of current-voltage relations in the membrane of the giant axon of Loligo. J Physiol. 1952 Apr;116(4):424–448. doi: 10.1113/jphysiol.1952.sp004716. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hagiwara S., Nakajima S. Differences in Na and Ca spikes as examined by application of tetrodotoxin, procaine, and manganese ions. J Gen Physiol. 1966 Mar;49(4):793–806. doi: 10.1085/jgp.49.4.793. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hille B. Pharmacological modifications of the sodium channels of frog nerve. J Gen Physiol. 1968 Feb;51(2):199–219. doi: 10.1085/jgp.51.2.199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- JULIAN F. J., MOORE J. W., GOLDMAN D. E. Membrane potentials of the lobster giant axon obtained by use of the sucrose-gap technique. J Gen Physiol. 1962 Jul;45:1195–1216. doi: 10.1085/jgp.45.6.1195. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lecar H., Ehrenstein G., Binstock L., Taylor R. E. Removal of potassium negative resistance in perfused squid giant axons. J Gen Physiol. 1967 Jul;50(6):1499–1515. doi: 10.1085/jgp.50.6.1499. [DOI] [PMC free article] [PubMed] [Google Scholar]
- NARAHASHI T., MOORE J. W., SCOTT W. R. TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS. J Gen Physiol. 1964 May;47:965–974. doi: 10.1085/jgp.47.5.965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakamura Y., Nakajima S., Grundfest H. The action of tetrodotoxin on electrogenic components of squid giant axons. J Gen Physiol. 1965 Jul;48(6):975–996. [PubMed] [Google Scholar]
- Pichon Y., Boistel J. Current-voltage relations in the isolated giant axon of the cockroach under voltage-clamp conditions. J Exp Biol. 1967 Oct;47(2):343–355. doi: 10.1242/jeb.47.2.343. [DOI] [PubMed] [Google Scholar]
