Firing Rate Oscillation and Stochastic Resonance in Cortical Networks With Electrical–Chemical Synapses and Time Delay

Abstract

The stochastic dynamics of neural network are studied and the phenomenon of stochastic resonance is found in inhibitory neurons, whose firing rate is close to the frequency of external stimulation. Time delay in the neural coupling process can induce multiple stochastic resonances, which appear intermittently at the integer multiples of the oscillation period of the input signal. It is found that the time delay can induce the periodic oscillation of neural firing rate, which may account for the occurrence of multiple stochastic resonances. In addition, the effect of synapses on firing rate oscillation and network resonance is investigated. As the strength of gap-junction and inhibitory-inhibitory chemical coupling is increased, the maximal resonant value increases, while the resonant frequency is unchanged. However, the resonant frequency and peak value increase with the coupling strength of excitatory–inhibitory chemical synapses. This difference may result from the interaction of excitation and inhibition within the cortical network. We further apply mean-field theory to time-delayed network model to validate the obtained numerical results. Both time delay and electrical–chemical synapses play an important role in firing rate oscillation and stochastic resonance within the cortical network, determining the ability to enhance the transmission of information in neural systems.