Firing Activity Induced by Nonidentical Signal Phases in Two Coupled Excitable Neurons

In this paper, we study the firing activity of two coupled excitable neurons with sub threshold periodic signalsfootnote{A sub threshold signal means that the signal is too weak to make the neuron firing.}. Particularly, we find that the two coupled excitable neurons can generate spikes to the sub threshold signals with no identical signal phases, indicating that the nonidentical signal phases play an active role for enhancing neuronal response to weak signals. Moreover, we find that regular spikes can be generated by neurons if the level of nonidentical signal phases is at an intermediate value and thus resulting in a resonance-like phenomenon. Furthermore, under the influence of nonidentical signal phases, the regularity of the firing activity also exhibits a resonance-like dependency on the value of coupling coefficient. Finally, we give a explanation to analyze the mechanism of these two types of resonance behavior. We believe that the phenomena found in this paper will be useful for designing neural information processing systems.