We have used the whole-cell patch-clamp technique to examine the ionic basis for a transient outward current in rabbit ventricular myocytes. High concentrations of intracellular calcium buffer prevented the current, isoproterenol increased it, and cadmium, nisoldipine, ryanodine, or caffeine blocked it. These data are consistent with a current that is calcium activated, by the calcium transient...

Cadmium block of calcium channels was studied in chicken dorsal root ganglion cells by a whole-cell patch clamp that provides high time resolution. Barium ion was the current carrier, and the channel type studied had a high threshold of activation and fast deactivation (type FD). Block of these channels by 20 microM external Cd2+ is voltage dependent. Cd2+ ions can be cleared from blocked chann...

The effect of neurokinin A (NKA) on neurons of bullfrog dorsal root ganglia (DRG) in primary culture was examined by using whole-cell patch-clamp methods. Application of NKA (1 microM) depolarized the DRG neurons, resulting in spontaneous firing of action potentials. Under voltage-clamp condition, NKA (3 nM-1 microM) caused an inward current (INKA) associated with decreased membrane conductance...

Intracellular polyamines inhibit the strongly rectifying IRK1 potassium channel by a mechanism different from that of a typical ionic pore blocker such as tetraethylammonium. As in other K(+) channels, in the presence of intracellular TEA, the IRK1 channel current decreases with increasing membrane voltage and eventually approaches zero. However, in the presence of intracellular polyamines, the...

A stretch-activated Cl- current (ICl) was investigated in cultured murine microglia using the whole-cell configuration of the patch-clamp technique. After application of membrane stretch, a Cl- current appeared within seconds, and its amplitude increased further within 3-8 min. ICl underwent rundown, which was prevented by addition of 4 mM ATP to the intracellular perfusing solution. The stretc...

Potassium and chloride channels were characterized in Asclepias tuberosa suspension cell derived protoplasts by patch voltage-clamp. Whole-cell currents and single channels in excised patches had linear instantaneous current-voltage relations, reversing at the Nernst potentials for K(+) and Cl(-), respectively. Whole cell K(+) currents activated exponentially during step depolarizations, while ...

Voltage clamp experiments were conducted using single ventricular myocytes which had been dissociated enzymatically from adult rat hearts in order to examine further the membrane currents which contribute to the unusual plateau of the rat action potential. Membrane currents were recorded, using a single microelectrode (switching) voltage clamp circuit. From holding potentials near the resting p...

Although D2 dopamine receptors have been localized to olfactory receptor neurons (ORNs) and dopamine has been shown to modulate voltage-gated ion channels in ORNs, dopaminergic modulation of either odor responses or excitability in mammalian ORNs has not previously been demonstrated. We found that <50 microM dopamine reversibly suppresses odor-induced Ca2+ transients in ORNs. Confocal laser ima...

In fault tolerance for parallel and distributed systems, message logging protocols have played a prominent role in the last three decades. Such enable local rollback to provide recovery from fail-stop errors. Global techniques can be straightforward implement but at times lead slower than rollback. Local is more complicated offer faster times. this work, we study power energy efficiency implica...