Abstract
Various degrees of pharmacological K inactivation were induced by Cs or Ba in isolated single electroplaques of the electric eel. The resulting changes in K conductance give rise to very different steady-state current-voltage characteristics. They also induce differences in ion dynamics during spike electrogenesis. The dynamic changes were studied by AC bridge methods, registering the changes in impedance in synchrony with the neurally or directly evoked spikes. While spike electrogenesis was virtually unaffected by addition of Cs or Ba, the patterns of impedance changes were very different. The various patterns are accounted for by the changes in the respective current-voltage characteristics. The data constitute new evidence for regarding the electrically excitable component of the reactive membrane as a heterogeneous electrochemical system with separate and independently reactive channels that in the electroplaques are permselective for Na and K, respectively.
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Selected References
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- ADRIAN R. H. THE RUBIDIUM AND POTASSIUM PERMEABILITY OF FROG MUSCLE MEMBRANE. J Physiol. 1964 Dec;175:134–159. doi: 10.1113/jphysiol.1964.sp007508. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BELTON P., GRUNDFEST H. Potassium activation and K spikes in muscle fibers of the mealworm Iarva (Tenebrio molitor). Am J Physiol. 1962 Sep;203:588–594. doi: 10.1152/ajplegacy.1962.203.3.588. [DOI] [PubMed] [Google Scholar]
- Finkelstein A., Mauro A. Equivalent Circuits as Related to Ionic Systems. Biophys J. 1963 May;3(3):215–237. doi: 10.1016/s0006-3495(63)86817-4. [DOI] [PMC free article] [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]
- Mullins L. J. A single channel or a dual channel mechanism for nerve excitation. J Gen Physiol. 1968 Sep;52(3):550–556. doi: 10.1085/jgp.52.3.550. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ozeki M., Freeman A. R., Grundfest H. The membrane components of crustacean neuromuscular systems. II. Analysis of interactions among the electrogenic components. J Gen Physiol. 1966 Jul;49(6):1335–1349. doi: 10.1085/jgp.0491335. [DOI] [PMC free article] [PubMed] [Google Scholar]