Recovering the passive properties of tapered dendrites from single and dual potential recordings

We demonstrate that measurement of the membrane potential at one or more sites on a branched and tapered neuron following a known transient injection of subthreshold somatic current uniquely determines the cellʹs passive electrical properties. That is, knowledge of the potentials allows recovery of the cellʹs axial resistance, membrane capacitance, membrane conductance and soma conductance. The argument underlying uniqueness leads immediately to a constructive, robust algorithm that we successfully test on synthetic data. The robustness stems from the fact that the algorithm requires only a few weighted integrals, or moments, of the measured potentials.