Oversampling method to extract excitatory and inhibitory conductances from single-trial membrane potential recordings.
Résumé
Variations of excitatory and inhibitory conductances determine the membrane potential (V(m)) activity of neurons, as well as their spike responses, and are thus of primary importance. Methods to estimate these conductances require clamping the cell at several different levels of V(m), thus making it impossible to estimate conductances from "single trial"V(m) recordings. We present here a new method that allows extracting estimates of the time course excitatory and inhibitory conductances from single-trace V(m) recordings. This method is based on oversampling of the V(m). We test the method numerically using models of increasing complexity. Finally, the method is evaluated using controlled conductance injection in cortical neurons in vitro using the dynamic-clamp technique. This conductance extraction method should be very useful for future in vivo applications.