Coherence resonance induced by the deviation of non-Gaussian noise in coupled Hodgkin-Huxley neurons.

Neurons are noisy elements. Noise arises from both intrinsic and extrinsic sources. In this paper, we numerically study the effect of a particular kind of colored non-Gaussian noise (NGN), mainly of its deviation q from Gaussian noise, on the collective firing in bidirectionally coupled deterministic Hodgkin-Huxley neurons. It is found that the coefficient of variation (CV), characterizing the temporal regularity of the collective spikes, nonlinearly changes with increasing q and passes through a minimum at an intermediate optimal q where the collective spiking becomes most regular, which represents the presence of coherence resonance (CR). We also present a global view of CV as a function of q and neuron number N under various appropriate values of noise intensity. For each value of noise intensity, there is an island present in the contour plot, which sufficiently demonstrates the phenomenon of "q-induced CR." This phenomenon, termed as q-induced CR, shows that there is an optimal deviation of the NGN by which the coupled neurons may behave most periodically in time. Our results provide a novel constructive role of the deviation of the NGN in information processing and signal transduction in real neural systems.