  Voltage and charge distributions in cellular microdomains regulate
communications, excitability, and signal transduction. We report here new
electrical laws in a cell, which follow from a nonlinear electro-diffusion
model. These newly discovered relations derive from the geometrical
cell-membrane properties, such as membrane curvature, volume, and surface area.
These electro-diffusion laws can now be used to predict and interpret voltage
distribution in cellular microdomains.
