Testing Methods for Synaptic Conductance Analysis Using Controlled Conductance Injection with Dynamic Clamp

Abstract

In this chapter, we present different methods to analyze intracellular recordings and the testing of these methods using dynamic-clamp techniques. The methods are derived from a model of synaptic background activity where the synaptic membrane conductances are considered as stochastic processes. Because this fluctuating point-conductance model can be treated analytically, different methods can be outlined to estimate different characteristics of synaptic noise from the membrane potential (V m) activity, such as the mean and variance of the excitatory and inhibitory conductance distributions (the VmD method) or spike-triggered averages of conductances. These analysis methods can be validated in controlled conditions using dynamic-clamp injection of known synaptic conductance patterns, as we illustrate here. Our approach constitutes a novel application of the dynamic clamp, which could be extended to the testing of other methods for extracting conductance information from the recorded V m activity of neurons.