BURSTING BEHAVIOR OF THE FITZHUGH-NAGUMO NEURON MODEL SUBJECT TO QUASI-MONOCHROMATIC NOISE

Noise-induced firing activity in the form of bursts of spikes is usual ly described by means of excitable systems that combine deterministic subthreshold oscillations with noise. In this paper, spontaneous burst ing activity is obtained by submitting the well-known FitzHugh-Nagumo (FHN) model to quasi-monochromatic noise (QMN), In the regime of inter est, the noise variable performs fast random oscillations with a fluct uating amplitude that varies in a slower time scale. Interspike interv al histograms (ISIHs) for the voltage variable of the FHN model are ob tained which, in some cases, show an imperfect phase locking between i nterspike intervals and both the period of the fundamental oscillatory component and the time scale of the random modulation of the noise. Q MN seems to be a good candidate to describe the intrinsic noisy oscill ations that lead to bursting in real neurons. (C) 1998 Elsevier Scienc e B.V.