Spontaneous rhythmical impedance changes in the trout’s egg

Abstract

The phenomena recorded in this paper were discovered by accident. During experiments on the impedance of trout’s eggs, it was found that under certain conditions the impedance varied in a rhythmical manner. This proved to be a property of live eggs and not of dead eggs and to be independent of the apparatus. The effect therefore was systematically examined. Before discussing this effect, some analysis or definition of the electrical term impedance with respect to biological systems is desirable. The impedance Z of any system is its resistance to the passage of an alternating electrical current. If the current is direct, the impedance is replaced by the resistance which is related to the impressed electric current by the relationship R = E / I , (1) where R = resistance, E = voltage, and I = current.