[Double polarized excitable system of the nerve fiber and its action potential (author's transl)]

An excitable tissue, namely a nerve or muscle fiber was regarded as an excitable system consisted of "field of excitation" and "active element" and the nerve fiber especially as a double polarized excitable system, because its equivalent circuit in resting state was constituted of two polarized layers. On the above view point, the author stated the action potential of the double polarized excitable system as the following. In the double polarized excitable system, the inner layer is polarized Em by itself, while the outer layer surrounding out side the inner layer is polarized Eo due to discharge current of Em. Then the cell potential (resting potential) Ec, the potential difference between in and out side of the system, is represented as Ec=Em-Eo. Excitation is referred to the temporary change of the equivalent circuit of resting state to that of excited state by temporary state by temporary reduce of resistance of inner layer nearly to zero, resulting temporary decrease of Em and change of Ec (action potential). Through the event, decrease of resistance of the inner layer is the root of the process, so was named active element, and the other electric constitution as field of excitation. Theoretically calculated and experimentally recorded action potential of this system showed every course of the action potential of the nerve fiber known already, including overshoot or undershoot (positive after potential).