Such enhanced changes in transmembrane potential are more readily detectable.

Compounds and methods for determining transmembrane potential, monitoring changes in transmembrane potential, and/or drug screening are provided.

The transmembrane potential of the membrane is predominantly set by the first or second ion channel, which are in dominant/recessive relationship and have opposite effects on the transmembrane potential.

A system is provided for stimulating one or more cells, wherein the stimulation is sub-threshold and may alter a transmembrane potential of the one or more cells.

Transmembrane potential measurement methods using cationic dyes, and anionic dyes are provided.

The membrane potential changes from -70 mV to +40 mV.

In a trice, the transmembrane voltage switches by about 100 mV.

For some populations of cells it may be possible to affect the transmembrane potential to gain a therapeutic benefit.

Healthy cells have a resting membrane potential of around – 70mV.

For some populations of cells it may be possible to affect the transmembrane potential to gain a therapeutic benefit.

Increased degree of spontaneous diastolic depolarization (phase 4 transmembrane potential).

The present system may provide sino-atrial cells with a local field stimulation that while not eliciting an action potential may nonetheless alter local transmembrane potential.

Increased degree of spontaneous diastolic depolarization (phase 4 transmembrane potential).

The rate of electron transfer, fluorescence intensity, and quenching are altered in response to changes in transmembrane potential.

The membrane voltage returns to the resting value shortly after hyperpolarization.