Behavior of delayed current under voltage clamp in the supramedullary neurons of puffer - PubMed (original) (raw)
Behavior of delayed current under voltage clamp in the supramedullary neurons of puffer
S Nakajima et al. J Gen Physiol. 1966 Mar.
Abstract
Depolarizations applied to voltage-clamped cells bathed in the normal solution disclose an initial inward current followed by a delayed outward current. The maximum slope conductance for the peak initial current is about 30 times the leak conductance, but the maximum slope conductance for the delayed current is only about 10 times the leak conductance. During depolarizations for as long as 30 sec, the outward current does not maintain a steady level, but declines first exponentially with a time constant of about 6 msec; it then tends to increase for the next few seconds; finally, it declines slowly with a half-time of about 5 sec. Concomitant with the changes of the outward current, the membrane conductance changes, although virtually no change in electromotive force occurs. Thus, the changes in the membrane conductance represent two phases of K inactivation, one rapidly developing, the other slowly occurring, and a phase of K reactivation, which is interposed between the two inactivations. In isosmotic KCl solution after a conditioning hyperpolarization there occurs an increase in K permeability upon depolarization. When the depolarizations are maintained, the increase of K permeability undergoes changes similar to those observed in the normal medium. The significance of the K inactivation is discussed in relation to the after-potential of the nerve cells.
Similar articles
- Analysis of K inactivation and TEA action in the supramedullary cells of puffer.
Nakajima S. Nakajima S. J Gen Physiol. 1966 Mar;49(4):629-40. doi: 10.1085/jgp.49.4.629. J Gen Physiol. 1966. PMID: 5943605 Free PMC article. - Transient K current in the somatic membrane of cultured central neurons of embryonic rat.
Rizzo MA, Nonner W. Rizzo MA, et al. J Neurophysiol. 1992 Nov;68(5):1708-19. doi: 10.1152/jn.1992.68.5.1708. J Neurophysiol. 1992. PMID: 1479440 - Kinetic study and numerical reconstruction of A-type current in granule cells of rat cerebellar slices.
Bardoni R, Belluzzi O. Bardoni R, et al. J Neurophysiol. 1993 Jun;69(6):2222-31. doi: 10.1152/jn.1993.69.6.2222. J Neurophysiol. 1993. PMID: 8394414 - 1S, 3R-ACPD induces a region of negative slope conductance in the steady-state current-voltage relationship of hippocampal pyramidal cells.
Lüthi A, Gähwiler BH, Gerber U. Lüthi A, et al. J Neurophysiol. 1997 Jan;77(1):221-8. doi: 10.1152/jn.1997.77.1.221. J Neurophysiol. 1997. PMID: 9120563
Cited by
- Structural correlates of selectivity and inactivation in potassium channels.
McCoy JG, Nimigean CM. McCoy JG, et al. Biochim Biophys Acta. 2012 Feb;1818(2):272-85. doi: 10.1016/j.bbamem.2011.09.007. Epub 2011 Sep 16. Biochim Biophys Acta. 2012. PMID: 21958666 Free PMC article. Review. - Facilitation of membrane electrical excitability in Drosophila.
Salkoff L, Wyman R. Salkoff L, et al. Proc Natl Acad Sci U S A. 1980 Oct;77(10):6216-20. doi: 10.1073/pnas.77.10.6216. Proc Natl Acad Sci U S A. 1980. PMID: 6255482 Free PMC article. - The kinetics of recovery and development of potassium channel inactivation in perfused squid (Loligo pealei) giant axons.
Chabala LD. Chabala LD. J Physiol. 1984 Nov;356:193-220. doi: 10.1113/jphysiol.1984.sp015460. J Physiol. 1984. PMID: 6097669 Free PMC article. - Analysis of depolarizing and hyperpolarizing inactivation responses in gymnotid electroplaques.
Bennett MV, Grundfest H. Bennett MV, et al. J Gen Physiol. 1966 Sep;50(1):141-69. doi: 10.1085/jgp.50.1.141. J Gen Physiol. 1966. PMID: 5971025 Free PMC article.
References
- J Physiol. 1959 Oct;148:188-200 - PubMed
- J Neurophysiol. 1962 Nov;25:772-89 - PubMed
- J Physiol. 1959 Oct;148:306-31 - PubMed
- Nature. 1959 Jan 24;183(4656):265-6 - PubMed
- Science. 1964 Oct 9;146(3641):266-8 - PubMed