Figure 4. Activation time constants of active conductances determine the frequencies for which they affect the LFP .

A, apical white‐noise current input (yellow star) to the cortical pyramidal cell model with a single linearly increasing quasi‐active conductance (as in middle column of Fig. 3 B). B, the quasi‐active conductance is either restorative (blue), passive‐frozen (black) or regenerative (red), and the PSD is shown for the somatic membrane potential $V_m$ (left panel), the somatic transmembrane currents $I_m$ (middle panel) and the LFP (right panel) at a position close to the soma (cyan dot). The activation time constant of the quasi‐active conductance is ${\tau }_w\left(V_R\right)=5\mathrm{ms}.$ C, as B, but with ${\tau }_w\left(V_R\right)=50\mathrm{ms}.$ D, as B, but with ${\tau }_w\left(V_R\right)=500\mathrm{ms}.$