Electrochemical Interpretation of Propagation of the Change in the Membrane Potential Using the Goldman‐Hodgkin‐Katz Equation

Abstract

Nerve conduction has been frequently explained by the Hodgkin‐Huxley equation based on the flow of K+ and Na+ across the cell membrane. By considering the relation between the membrane potential and the membrane current based on the Goldman‐Hodgkin‐Katz equation, it becomes clear that the conventional analysis using the voltage‐clamp method is not correct and that the hyperpolarization condition is artificially made. Taking into account the channel functions and the electronic properties, we suggested a new propagation mechanism. When the nerve cell is excited by an external stimulus, the ligand‐gated channels at the synapse serve as an electric power source to propagate the change in the membrane potential to the synapse terminal along the axon and the voltage‐gated channels at the axon locally assist the directional propagation along the axon.

Severe Problems of the Voltage‐Clamp Method in Concurrent Monitoring of Membrane Potentials

“…When we switched from AP to RP cell in the electric circuit (at t = 5.000 s), the reverse circulating currents were locally generated by the local ion transfers, and the membrane potentials returned to the resting potential (at t = 9.000 s). The hyperpolarization was not observed in all the cells because the resting potential was equal to the theoretical value determined by the ratio of K + concentration only [24]. Similar results were obtained when the membrane potential was not clamped and was clamped with R S = 1 or 10 kΩ.…”

“…A liquid‐membrane cell comprises two aqueous phases (W1 and W2) and a nitrobenzene phase (NB), as described in Figure SI‐1 [23, 24]. The NB solution was impregnated in a porous polytetrafluoroethylene membrane filter T100A025A (pore size: 1 μm, thickness: 75 μm, ADVANTEC TOYO KAISHA, Ltd., Japan), and the filter was used as a liquid membrane (LM).…”

“…The authors' group has elucidated the propagation of the change in the membrane potential using a nervemodel-cell system with multiple liquid-membrane cells [16][17][18][19][20][21][22][23][24]. Several liquid-membrane cells were connected using a switch, multiple relay switches, and multiple timers within the electric circuit to mimic a function of K + and Na + channels [20,21].…”