title: Calculating event-triggered average synaptic conductances from the membrane potential.
abstract: The optimal patterns of synaptic conductances for spike generation in central neurons is a subject of considerable interest. Ideally such conductance time courses should be extracted from membrane potential (V(m)) activity, but this is difficult because the nonlinear contribution of conductances to the V(m) renders their estimation from the membrane equation extremely sensitive. We outline here a solution to this problem based on a discretization of the time axis. This procedure can extract the time course of excitatory and inhibitory conductances solely from the analysis of V(m) activity. We test this method by calculating spike-triggered averages of synaptic conductances using numerical simulations of the integrate-and-fire model subject to colored conductance noise. The procedure was also tested successfully in biological cortical neurons using conductance noise injected with dynamic clamp. This method should allow the extraction of synaptic conductances from V(m) recordings in vivo.
authors.affiliation: Unité de Neurosciences Intégratives et Computationnelles, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Pospischil
authors.forename: Zuzanna
authors.initials: Z
authors.lastname: Piwkowska
authors.forename: Michelle
authors.initials: M
authors.lastname: Rudolph
authors.forename: Thierry
authors.initials: T
authors.lastname: Bal
authors.forename: Alain
authors.initials: A
authors.lastname: Destexhe
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004553:Electric Conductivity; D004558:Electric Stimulation / Q000379:methods; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D009778:Occipital Lobe / Q000166:cytology; D018408:Patch-Clamp Techniques / Q000379:methods; D013569:Synapses / Q000502:physiology* / Q000528:radiation effects