Calculating event-triggered average synaptic conductances from
the membrane potential.
Martin Pospischil, Zuzanna Piwkowska, Michelle Rudolph, Thierry
Bal and Alain Destexhe.
Journal of Neurophysiology 97: 2544-2552, 2007.
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
(Vm) activity, but this is difficult because the nonlinear
contribution of conductances to the Vm 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 Vm 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 Vm recordings in vivo.
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