High Quality Content by WIKIPEDIA articles! Classical cable theory uses mathematical models to calculate the flow of electric current (and accompanying voltage) along passive neuronal fibers (neurites) particularly dendrites that receive synaptic inputs at different sites and times. Estimates are made by modeling dendrites and axons as cylinders composed of segments with capacitances and resistances combined in parallel (See Figure 1). The capacitance of a neuronal fiber comes about because electrostatic forces are acting through the very thin phospholipid bilayer (See Figure 2). The resistances in series along the fiber is due to the cytosol’s significant resistance to movement of electric charge.