Title : Estimation of synaptic conductances and their variances from intracellular recordings of neocortical neurons in vivo
Authors : Michelle Rudolph, Joe Guillaume Pelletier, Denis Pare and Alain Destexhe
Year : 2004
Journal : Neurocomputing
Volume : 58-60
Pages : 387-392
During intense network activity, neocortical neurons are in a “high-conductance” state. To es- timate the respective contributions of excitatory and inhibitory conductances in generating such states, we combined computational models with intracellular recordings obtained in cat parietal cortex in vivo. Fitting a 6uctuating-conductance model to the recordings revealed that inhibitory conductances are dominant (several times larger than excitation). Conductance variance (i.e., the “noise”) was also larger for inhibition, indicating that inhibitory dynamics have a pronounced impact on membrane potential 6uctuations. We conclude that the synaptic bombardment of neo- cortical neurons in vivo is not excitatory, but mostly determined by inhibitory conductances.