TWO KINDS OF MULTI-MODE NEURAL FIRING RHYTHMS INDUCED BY EXTERNAL PERIODIC PULSE STIMULUS IN FITZHUGH-NAGUMO MODEL
Wei Ren · Acta Biophysica Sinica · 2008
The present study demonstrated the different characteristics and generation conditions of stochastic and chaotic multi-mode neural firing patterns caused by external periodic pulse stimulus. The peak amplitudes of interspike intervals (ISIs) histogram of the stochastic firing pattern decreased exponentially. Such ISI series could not be predicted and exhibited a complexity approaching 1. The peak amplitudes of the chaotic bursting did not decrease exponentially. The chaotic ISI series could be predicted and exhibited a complexity much less than 1. The chaotic ISI series were induced by intensive external pulse stimulation with periods shorter than the internal period of the neuronal system. Chaotic firing appeared only within a very limited parameter range. The stochastic firing patterns were induced by pulse stimulation with periods longer than the internal period. The stochastic firings were resulted from the cooperation between periodic pulse and the noise in a large range of parameter values. The results indicate the different dynamics of stochastic and chaotic multi-mode firing patterns and provide practical approaches to distinguish them.