Abstract
The action of a number of agents, which may be classified as "stabilizers" and "unstabilizers" on the electrical oscillations and after-potentials in the squid giant axon has been examined. The effects on the spike, "positive overshoot," and "potassium potential" were also observed, but where possible concentrations were employed which left these phenomena unaltered. Veratrine augmented the oscillations and the negative after-potential, particularly with repetitive stimulation. Yohimbine caused a small long lasting positive after-potential and depressed the oscillations, effects also enhanced with repetitive activity. Cocaine and procaine suppressed the oscillations and the negative after-potential but DDT was completely inert. An elevation in the medium calcium depressed the oscillations and the naturally occurring negative after-potential; negative after-potentials induced with veratrine were increased by calcium. A decrease in the potassium augmented the oscillations and the negative after-potential. A hypothesis is presented in which these effects are interpreted in terms of potassium concentration at the fiber surface as regulated by a labile permeability and metabolism. This is discussed in relation to the available evidence for these factors. It is a pleasure to acknowledge the author's indebtedness to Dr. D. E. S. Brown, Director, and to his staff at the Bermuda Biological Station for Research for the cooperation and special facilities provided during the initiation of this work. Dr. T. Baylor of Princeton University very kindly provided the camera and film used in Bermuda.
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Selected References
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- Boyle P. J., Conway E. J. Potassium accumulation in muscle and associated changes. J Physiol. 1941 Aug 11;100(1):1–63. doi: 10.1113/jphysiol.1941.sp003922. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bugnard L., Hill A. V. Electric excitation of the fin nerve of sepia. J Physiol. 1935 Mar 15;83(4):425–438. doi: 10.1113/jphysiol.1935.sp003240. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hodgkin A. L., Huxley A. F. Potassium leakage from an active nerve fibre. J Physiol. 1947 Jul 31;106(3):341–367. doi: 10.1113/jphysiol.1947.sp004216. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hodgkin A. L. The effect of potassium on the surface membrane of an isolated axon. J Physiol. 1947 Jul 31;106(3):319–340. doi: 10.1113/jphysiol.1947.sp004215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schmitt F. O., Schmitt O. H. Partial excitation and variable conduction in the squid giant axon. J Physiol. 1940 Mar 14;98(1):26–46. doi: 10.1113/jphysiol.1940.sp003832. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shanes A. M. An Experimental and Theoretical Approach to the Mechanism of Cocaine Action. Science. 1948 Jun 25;107(2791):679–681. doi: 10.1126/science.107.2791.679-a. [DOI] [PubMed] [Google Scholar]
- Solandt D. Y. The effect of potassium on the excitability and resting metabolism of frog's muscle. J Physiol. 1936 Feb 8;86(2):162–170. doi: 10.1113/jphysiol.1936.sp003351. [DOI] [PMC free article] [PubMed] [Google Scholar]