Transient potassium currents in mammalian central neurons influence both the repolarization of single action potentials and the timing of repetitive action potential generation. How these currents are integrated into neuronal function will depend on their specific properties: channel availability at the resting potential, activation threshold, inactivation rate, and current density. We here rep...

We investigated the ionic interactions responsible for the characteristic nonrepetitive spike activity of amacrine cells. First we measured 4 pharmacologically separable ionic components: a voltage-gated, transient inward sodium current, a voltage-gated, sustained inward calcium current, a calcium-gated, sustained outward potassium current, and a voltage-gated, transient outward potassium curre...

AIM To examine the effect of BmTx3B, a novel short-chain peptide isolated from the venom of Asian scorpion Buthus martensi Karsch, on voltage-gated potassium channels. METHODS Two types of voltage-dependent potassium currents were recorded from dissociated hippocampal neurons of neonatal rat in whole-cell voltage-clamp mode, and separated based upon their kinetic properties. RESULTS BmTx3B ...

The involvement of the AGC protein kinase family in regulating arrhythmia has drawn considerable attention, but the underlying mechanisms are still not clear. The aim of this study is to explore the role of 3-phosphoinositide-dependent protein kinase-1 (PDK1), one of upstream protein kinases of the AGC protein kinase family, in the pathogenesis of dysregulated electrophysiological basis. PDK1(F...

Inward rectifier potassium currents are present in different types of cells. In the heart, the inward rectifier potassium current IK1 plays a crucial role in maintaining cardiac resting membrane potential and excitability. It is generally believed that the strong inward rectification of cardiac IK1 channels makes it conduct substantial current near the resting potential but carry little or no c...

This study presents a modified transient current limiter (MTCL) for mitigation the inrush current of transformers. The MTCL is based on conventional transient current limiter (TCL), which, its configuration is modified to overcome the TCL drawbacks of operation. The proposed MTCL offers lower power losses and voltage/current THD during normal operation mode. It needs only one limiting reactor i...

Hippocampal neurons exhibit three voltage-gated potassium currents, two transient currents and a delayed rectifier, that influence numerous aspects of electrogenesis including action potential duration and accommodation to sustained depolarization. These currents, termed A-, D-, and K-currents, respectively, can be distinguished based on kinetics, steady state inactivation characteristics, and ...

The Kv4 subfamily of voltage-gated potassium channels is responsible for the transient A-type potassium current that operates at subthreshold membrane potentials to control membrane excitability. Arachidonic acid was shown recently to modulate both the peak amplitude and kinetics of the hippocampal A-current. However, in Xenopus oocytes, arachidonic acid only inhibited the peak amplitude of Kv4...