Oscillations of synchronization in inhibitory coupled Hodgkin-Huxley neurons network

We investigate the dynamics of complex network of Hodgkin-Huxley neurons. It consists of 3 sub-networks. The first small network receives external signal which is transferred into a spike sequence. Then it is transmitted to two small-world networks interacting via an inhibitory coupling and working together to process the signal. We observe that the synchronization index (SI) in both networks periodically changes in time: the time intervals with the high SI alternate with the time intervals where SI is low. We calculate correlation between them and find that when adjusting the strength of the inhibitory coupling one can observe SI in these networks changes either in phase or out of phase.