Neurocomputing 65–66 (2005) 685–690 Subthreshold cross-correlations between cortical neurons: A reference model with static synapses Ofer Melamed a,b , Gilad Silberberg b , Henry Markram b , Wulfram Gerstner c , Magnus J.E. Richardson c,Ã a Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel b Laboratory of Neural Microcircuitry, Brain Mind Institute, EPFL 1015, Lausanne, Switzerland c Laboratory of Computational Neuroscience, I&C and Brain Mind Institute, EPFL, 1015 Lausanne, Switzerland Available online 15 December 2004 Abstract The structure of cross-correlations between subthreshold potentials of neocortical neurons was recently examined. Characteristic features included broad widths and significant peak advances. It was suggested that dynamic synapses shape these cross-correlations. Here a reference model is developed comprising leaky integrators with static synapses. The forms of thesubthresholdcorrelationsarederivedanalyticallyfortwodifferentformsofsynapticinput: steadydriveandpopulationsbursts.Forthelattercasethemodelcapturesthewidthsseenin experiment.However,themodelcouldnotaccountforthepeakadvance.Itisconcludedthat models with static synapses lack the necessary biological details for describing cortical dynamics. r 2004 Elsevier B.V. All rights reserved. Keywords: Neocortex; Microcircuit; Correlations; Subthreshold ARTICLE IN PRESS www.elsevier.com/locate/neucom 0925-2312/$-see front matter r 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.neucom.2004.10.098 Ã Corresponding author. E-mail address: Magnus.Richardson@epfl.ch (M.J.E. Richardson).