Abstract
1. The transient potassium current was recorded in single hippocampal CA1 neurones from the rat by use of the whole-cell patch clamp technique. The effects on this current of a homologous series of aliphatic alcohols, ranging from butanol to octanol, were investigated. 2. The predominant effect of octanol (and the other alcohols) was to cause an increase in the initial rate of decay of the transient potassium current together with a slight decrease in the rate of decay of later phases of the current, such that the current decay became markedly non-monotonic. The alcohols also caused a decrease in peak current amplitude which could not be accounted for solely by the change in current decay kinetics. 3. The effect of the alcohols was concentration-dependent and readily reversible. Increasing chain length increased the potency of each alcohol by about 3 fold for each methylene group added. Other than a difference in potency, there appeared to be little difference in the action of aliphatic alcohols of different chain length on the transient current. 4. The alcohols did not appreciably change the voltage-dependence of steady state inactivation or activation of the transient potassium current. 5. The rate of inactivation of the transient current in these cells was only weakly voltage-dependent. This weak voltage-dependence was not changed by the presence of aliphatic alcohols, neither was the effect of the alcohols themselves voltage-dependent. 6. The potencies of each of the aliphatic alcohols were well correlated with their respective membrane/buffer partition coefficients, a finding which implies a hydrophobic locus of action.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 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]
- Adams P. R. Drug blockade of open end-plate channels. J Physiol. 1976 Sep;260(3):531–552. doi: 10.1113/jphysiol.1976.sp011530. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Connor J. A., Stevens C. F. Voltage clamp studies of a transient outward membrane current in gastropod neural somata. J Physiol. 1971 Feb;213(1):21–30. doi: 10.1113/jphysiol.1971.sp009365. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fenwick E. M., Marty A., Neher E. A patch-clamp study of bovine chromaffin cells and of their sensitivity to acetylcholine. J Physiol. 1982 Oct;331:577–597. doi: 10.1113/jphysiol.1982.sp014393. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Forman S. A., Miller K. W. Molecular sites of anesthetic action in postsynaptic nicotinic membranes. Trends Pharmacol Sci. 1989 Nov;10(11):447–452. doi: 10.1016/S0165-6147(89)80009-4. [DOI] [PubMed] [Google Scholar]
- Gage P. W., McBurney R. N., Schneider G. T. Effects of some aliphatic alcohols on the conductance change caused by a quantum of acetylcholine at the toad end-plate. J Physiol. 1975 Jan;244(2):409–429. doi: 10.1113/jphysiol.1975.sp010806. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haydon D. A., Urban B. W. The action of alcohols and other non-ionic surface active substances on the sodium current of the squid giant axon. J Physiol. 1983 Aug;341:411–427. doi: 10.1113/jphysiol.1983.sp014813. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haydon D. A., Urban B. W. The actions of some general anaesthetics on the potassium current of the squid giant axon. J Physiol. 1986 Apr;373:311–327. doi: 10.1113/jphysiol.1986.sp016049. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Llinás R. R. The intrinsic electrophysiological properties of mammalian neurons: insights into central nervous system function. Science. 1988 Dec 23;242(4886):1654–1664. doi: 10.1126/science.3059497. [DOI] [PubMed] [Google Scholar]
- Murrell R. D., Braun M. S., Haydon D. A. Actions of n-alcohols on nicotinic acetylcholine receptor channels in cultured rat myotubes. J Physiol. 1991 Jun;437:431–448. doi: 10.1113/jphysiol.1991.sp018604. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nakajima Y., Nakajima S., Leonard R. J., Yamaguchi K. Acetylcholine raises excitability by inhibiting the fast transient potassium current in cultured hippocampal neurons. Proc Natl Acad Sci U S A. 1986 May;83(9):3022–3026. doi: 10.1073/pnas.83.9.3022. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Numann R. E., Wadman W. J., Wong R. K. Outward currents of single hippocampal cells obtained from the adult guinea-pig. J Physiol. 1987 Dec;393:331–353. doi: 10.1113/jphysiol.1987.sp016826. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oxford G. S., Swenson R. P. n-Alkanols potentiate sodium channel inactivation in squid giant axons. Biophys J. 1979 Jun;26(3):585–590. doi: 10.1016/S0006-3495(79)85273-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelzer D., Trautwein W. Currents through ionic channels in multicellular cardiac tissue and single heart cells. Experientia. 1987 Dec 1;43(11-12):1153–1162. doi: 10.1007/BF01945515. [DOI] [PubMed] [Google Scholar]
- Saint D. A., Thomas T., Gage P. W. GABAB agonists modulate a transient potassium current in cultured mammalian hippocampal neurons. Neurosci Lett. 1990 Oct 2;118(1):9–13. doi: 10.1016/0304-3940(90)90236-3. [DOI] [PubMed] [Google Scholar]
- Seeman P. The membrane actions of anesthetics and tranquilizers. Pharmacol Rev. 1972 Dec;24(4):583–655. [PubMed] [Google Scholar]
- Storm J. F. Temporal integration by a slowly inactivating K+ current in hippocampal neurons. Nature. 1988 Nov 24;336(6197):379–381. doi: 10.1038/336379a0. [DOI] [PubMed] [Google Scholar]
- Surmeier D. J., Stefani A., Foehring R. C., Kitai S. T. Developmental regulation of a slowly-inactivating potassium conductance in rat neostriatal neurons. Neurosci Lett. 1991 Jan 14;122(1):41–46. doi: 10.1016/0304-3940(91)90188-y. [DOI] [PubMed] [Google Scholar]
- Treistman S. N., Wilson A. Alkanol effects on early potassium currents in Aplysia neurons depend on chain length. Proc Natl Acad Sci U S A. 1987 Dec;84(24):9299–9303. doi: 10.1073/pnas.84.24.9299. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wachtel R. E. Aliphatic alcohols increase the decay rate of glutamate-activated currents at the crayfish neuromuscular junction. Br J Pharmacol. 1984 Oct;83(2):393–397. doi: 10.1111/j.1476-5381.1984.tb16499.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
