An Analysis of the Current‐Voltage Relationship in Excitable Nitella Cells

Experiments were performed on cells of the fresh water algae Nitella using “triangular waves” of varying frequencies, i. e. depolarizing‐hyperpolarizing currents with varying, linear slopes. With very low frequencies one obtains “steady state rectification” curves, but with intermediate frequencies instability phenomena are revealed. The experimental findings of “dynamic current‐voltage” characteristics are compared with the theoretical results, which can be predicted from the author's “electrohydraulic” hypothesis for excitability phenomena. It is suggested that electro‐osmotic processes, arising from presence of membrane fixed charges, may play a part in the excitability of Nitella.