The inotropic effects of ACh and adenosine on ferret ventricular cells were investigated with the action potential-clamp technique. Under current clamp, both agonists resulted in action potential shortening and a decrease in contraction. Under action potential clamp, both agonists failed to decrease contraction substantially. In the absence of agonist, application of the short action potential ...

Extracellular excitation of neurons is applied in studies of cultured networks and brain tissue, as well as in neuroprosthetics. We elucidate its mechanism in an electrophysiological approach by comparing voltage-clamp and current-clamp recordings of individual neurons on an insulated planar electrode. Noninvasive stimulation of neurons from pedal ganglia of Lymnaea stagnalis is achieved by def...

This paper discusses the design considerations for low conversion ratio voltage regulation modules (VRM’s) for the next generation of microprocessors, focusing on the handling of large, high-slew-rate current transients. A converter topology which deploys an inductive clamp to handle the unloading transients, while operating at a modest switching frequency, low current ripple, and low power dis...

A "slow" inward current (Is) has been identified in ventricular muscle and Purkinje fibers of several mammalian species. The two-microelectrode voltage clamp technique is used to examine some of the relationships between Is and contraction of the sheep cardiac Purkinje fiber. "Tails" of inward current occurring on repolarization and extrapolation of Is recovery each show that the Is system may ...

With the consideration of low standby leakage in nanoscale CMOS processes, a new 2×VDD-tolerant ESD clamp circuit was presented in this paper. The new ESD clamp circuit had a high-voltage-tolerant ESD detection circuit to improve the turn-on efficiency of the silicon-controlled-rectifier-based (SCRbased) ESD device. This design had been successfully verified in a 65-nm CMOS process. The leakage...

A new power-rail ESD clamp circuit designed with PMOS as main ESD clamp device has been proposed and verified in a 65nm 1.2V CMOS process. The new proposed design with adjustable holding voltage controlled by the ESD detection circuit has better immunity against mis-trigger or transient-induced latch-on event. The layout area and the standby leakage current of this new proposed design are much ...

Patch-clamp recording is undoubtedly the leading method for studying the behaviour of ion channels. In 1976, Neher and Sakmann (1) first used the cell-attached configuration of the patch-clamp technique to resolve current flow through single acetylcholine-activated cation channels in frog skeletal muscle. Subsequent improvements to the technique produced a range of methods for the high resoluti...

The purpose of this report is to introduce a holistic approach to voltage clamp data. By voltage clamping excitable membranes, in the whole-cell or single-channel level, it is possible to define four basic types of parameters: kinetic (e.g. time and rate constants), "size" (e.g. current, conductance and permeability), selectiviO, to certain ions over others and dependence of these parameters on...

Ion channels are essential in a wide range of cellular functions and their malfunction underlies many disease states making them important targets in drug discovery. The availability of standardized cell lines expressing ion channels of interest lead to the development of diverse automated patch clamp (APC) systems with high-throughput capabilities. These systems are now available for drug scre...