Extracting information from the power spectrum of voltage noise

We outline an approximation for obtaining an analytic expression of the power spectral density (PSD) of the membrane potential ðVmÞ in neurons subject to synaptic noise. In highconductance states, there is a remarkable agreement between this approximation and PSDs computed numerically. This analytic expression can be used to predict how the PSD depends on the exact kinetic model for synaptic currents, as well as on the values of the rate constants. This approach can therefore yield methods to estimate the characteristics of the kinetics of individual synaptic conductances from the analysis of the Vm activity in intracellular recordings in vivo. r 2004 Elsevier B.V. All rights reserved.