Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-21097
Pflugers Arch 1994 Jul 01;4275-6:399-405.
Show Gene links Show Anatomy links

Kinetic mode switch of rat brain IIA Na channels in Xenopus oocytes excised macropatches.

Fleig A , Ruben PC , Rayner MD .


???displayArticle.abstract???
Na currents recorded from outside-out macropatches excised from Xenopus oocytes expressing the alpha subunit of the rat brain Na channel IIA show at least two distinguishable components in their inactivation time course, with time constants differing about tenfold (tau h1 = approx. 150 microseconds and tau h2 = approx. 2 ms). In excised patches, the inactivation properties of Na currents changed with time, favoring the faster inactivation kinetics. Analysis of the fast and slow current kinetics shows that only the relative magnitudes of tau h1 and tau h2 components are altered without significant changes in the time constants of activation or inactivation. In addition, voltage dependence of both activation and steady-state inactivation of Na currents are shifted to more negative potentials in patches with predominantly fast inactivation, although reversal potentials and valences remained unaltered. We conclude that the two inactivation modes discerned in this study are conferred by two states of Na channel the interconversion of which are regulated by an as yet unknown mechanism that seems to involve cytosolic factors.

???displayArticle.pubmedLink??? 7971138

???displayArticle.grants??? [+]

Species referenced: Xenopus laevis
Genes referenced: hes4 mapt

References [+] :
Alzheimer, Modal gating of Na+ channels as a mechanism of persistent Na+ current in pyramidal neurons from rat and cat sensorimotor cortex. 1993, Pubmed