Basic Electrophysiology
Benjamin Franklin pointed out the boundless possibilities for error allowed by human imagination. Luigi Galvani was nonetheless correct in his most important conclusions that the underlying mechanism of the transmission of information by nerves is electrical rather than mechanical, and that the sources of the required electrical energy lie within the tissue itself. A remarkable aspect of electrically active cells is that the voltage of the inside with respect to the outside is significantly negative when the cell is at rest. Sodium ion channels are mostly closed at rest and can remain closed indenitely. Leakage channels are relatively small but allow small numbers of any small ion species to pass from the inside to the outside, or vice versa.