Self-organized synchronous oscillations in a network of excitable cells coupled by gap junctions

Recent evidence suggests that electrical coupling plays a role in generatin g oscillatory behaviour in networks of neurons; however, the underlying mec hanisms have not been identified. Using a cellular automata model proposed by Traub et at (Traub R D, Schmitz D, Jefferys J G and Draguhn A 1999 High- frequency population oscillations are predicted to occur in hippocampal pyr amidal neural networks interconnected by axo-axonal gap junctions Neuroscie nce 92 40726), we describe a novel mechanism for self-organized oscillation s in networks that have strong, sparse random electrical coupling via gap j unctions. The network activity is generated by random spontaneous activity that is moulded into regular population oscillations by the propagation of activity through the network. We explain how this activity gives rise to pa rticular dependences of mean oscillation frequency on network connectivity parameters and on the rate of spontaneous activity, and we derive analytica l expressions to approximate the mean frequency and variance of the oscilla tions. In doing so, we provide insight into possible mechanisms for frequen cy control and modulation in networks of neurons.