Box 1.

Detailed description of Eq. 1

The capacity current [1] depends on the membrane capacitance ($C_M$) and the change in the displacement of the membrane potential from it resting value over time $\left(\frac{\text{d}V}{\text{d}t}\right)$. The ionic current is further divided into a potassium ion ($K$) current [2], a sodium ion ($\mathit{Na}$) current [3] and a leakage current of other ions ($L$) [4]. Each of the ionic currents depends on the permeability of the neural membrane for the respective ion species and is described in terms of an ionic conductance ($g_{\mathit{ion}}$), which is the inverse of the electrical resistance, and a driving force, which is the result of the difference between the displacement of the membrane potential from its resting value ($V$) and the equilibrium potential for the ion given as a displacement from the resting membrane potential ($V_{\mathit{ion}}$).