Fig. 2.
Input conductance estimation. A: mean Vm recorded for four different levels of current injection during dynamic random chord (DRC) and noise stimulation. Input conductance, G, was estimated at each time point in the stimulus. The broken line indicates a single time point 100 ms into the stimulus for which we estimated a single value of G. B: open circles indicate the Vm recorded at this time point for 25 stimulus repetitions for the four levels of current injection. Blue triangles indicate mean Vm values plotted in A. G could be estimated at this time point from these responses by examining the relationship between injected current and recorded Vm response. This relationship was modeled by fitting a line to these data as Ohm’s law predicts that this relationship should be linear. C: the inverse of the slope of the linear fit was used as the estimate for G for this time point. D: using Ohm’s law, the Vm could be reconstructed from this estimate for G and the known levels of current injection, to validate the estimates. This was necessary as neurons are not perfectly linear devices. Iinj, injected current; Vm, membrane potential.