Using computer simulation of electrical processes in a GABA-ergic interneuronal network, we found that synchronization of electrical discharges of the neurons is critically dependent on the geometrical size of the virtual network. If the size, under our simulation conditions, was either lesser than 2,1 mm or greater than 4,2 mm, the network was not able to generate synchronous discharges. Our findings may explain the geometrical size-dependent gamma rhythm generated by neurons of the hippocampal networks.