Long-lasting transients of activation in neural networks

Abstract

The question has been investigated whether long-lasting transients of activation (i.e. slow waves), observed to occur in the intact cerebral cortex (EEG ‘delta’ waves and ‘K’ complexes) as well as an isolated tissue cultured in vitro, can also emerge in a simplified neural network model of interconnected excitatory and inhibitory cells. It is shown that slow waves can indeed occur even if the cells in the network do not have explicitly built-in slow processes. The mechanism underlying the termination of transient activity depends crucially upon the presence of a refractory period and random activity, rather than upon inhibitory suppression. A wide range of characteristic unit firing patterns is associated with transient population activities, even though all the cells in the network model have identical response properties.