- Abstract We present a long-term (hours) measurements of the spontaneous activity of cortical cells 2D neural network placed on multi-electrodes arrays. We compare the histogram of the single neurons inter spike interval and the network inter synchronized bursting events interval. In addition, the effect of Ca concentration on the network activity is being studied. Under 1 mM Ca concentration the network exhibits periodic synchronized bursting. We present a novel feedback regulated integrate & fire model to account of the observations. In the model we include two additional features of dynamical threshold and synapses fatigue.