It has already been stated, based on experimental evidence, that ”the membrane permeability to the ions has nothing to do with the potential generation and the ions’ adsorption on the membrane surface generates the membrane potential”; for a review, see [74]. The idea itself is nonsense: in a balanced state, no ion transport happens, so even without permeability, the balanced state persists; the resting potential has nothing to do with either ions’ mobility or permeability or with ion absorption [75]. Furthermore, there is no idea in Goldman-Hodgkin-Katz (GHK) about whether the ’setpoint’ (why that specific concentration or potential difference) is present and why the same potential is reset after rough perturbations such as issuing an AP or replicating a cell. The causality is reversed: the potential is a static concept and is set electrically, and the two gradients form the experienced concentrations from the available solvent molecules. For the time course of gradient formation, mobility and permeability play a role, but not in determining concentrations or the resting potential.
In our clear physical picture, the thermodynamic forces on one side and on the other side of the membrane are summed. They counterbalance each other; furthermore, jointly the effect of the neuronal condenser, see Fig. 1.5. As we emphasized, the concentration gradients are ion-specific. Furthermore, as discussed in connection with Eq.(2.20), the Nernst equation comprises a per-ion indefinite constant (a potential difference). To calculate a linear combination of terms comprising an arbitrary constant is nonsense, and so is adding absolute concentrations on the different sides of the membrane, or changing the base of the logarithm used in a calculation to match the experimental value. It is not more than number magic. The potential is described by coupled equations as discussed in connection with Eq. (1.2).
The ions do not fit into the GHK picture. One of the reasons why GHK cannot be good is that is omitted. Biologically, it is hard to believe that does not participate in the game of life (especially since biology sees the need for pumps). Physically, a single concentration on one side of the membrane cannot maintain balance; as the different ion-exchange processes shown in Table 3.1 and Fig. 1.5 demonstrate. When adding a new ion to the solution, the sum concentration increases, and so the electrical force increases, forcing the previous elements to find new concentrations on both sides. The appearance of a new chemical element indirectly changes the concentrations of the others (a good example is the role of the negligible amount of ).