Abstract

Neocortical neurons in vivo operate in a high-conductance state which may affect the dynamics of dendritic integration, but this aspect remains only barely characterized. We investigated this problem by using biophysical models of morphologically-reconstructed neocortical pyramidal neurons in which isolated and paired synaptic events were studied according to their dendritic location. We show that during active states, there is an ongoing dynamics of randomly occurring forward- and back-propagating dendritic action potentials. This dynamics determinantly impacts on how individual or paired synaptic events interact, leading to a type of integrative behavior which is different from classical models of dendritic integration.