Multielectrode array recordings of extracellular electrical field potentials along the depth axis of the cerebral cortex is an up-and-coming approach for investigating activity of cortical neuronal circuits (Einevoll et al., J. Neurophysiol., 2007; Blomquist et al., PLoS Comp. Biol., 2009). The low-frequency band of extracellular potential, i.e., the local field potential (LFP), is assumed to reflect the synaptic activity and can be used to extract the current source density (CSD) profile. However, physiological interpretation of CSD profile is uncertain because it does not disambiguate synaptic inputs from passive return currents or identifies population-specific contributions to the signal thus obfuscating its interpretation in terms of the excitation flow in the columnar microcircuit.Here we present a novel anatomically informed model for decomposing the LFP signal into population-specific contributions and for estimating the corresponding laminar profiles of synaptic inputs. This involves a combination of 1) the linear forward model, which predicts population-specific laminar LFP in response to synaptic inputs applied to the population of cells having realistic morphologies; and 2) the linear inverse model, which reconstructs laminar profiles of synaptic inputs from laminar LFP data based on the forward prediction. Assuming spatial correlation of synaptic inputs within individual populations, the model decomposes the columnar LFP into population-specific contributions and estimates the corresponding synaptic input laminar profiles less the mean value. Constraining the solution with a priori knowledge of the spatial distribution of synaptic connectivity further allows estimating the strength of active synaptic projections from the columnar LFP profile thus fully specifying synaptic inputs.The capability of the model is demonstrated by applying it to the experimental extracellular data.