Title
Determination of firing times for the stochastic Fitzhugh-Nagumo neuronal model
Abstract
We present for the first time an analytical approach for determining the time of firing of multicomponent nonlinear stochastic neuronal models. We apply the theory of first exit times for Markov processes to the Fitzhugh-Nagumo system with a constant mean gaussian white noise input, representing stochastic excitation and inhibition. Partial differential equations are obtained for the moments of the time to first spike. The observation that the recovery variable barely changes in the prespike trajectory leads to an accurate one-dimensional approximation. For the moments of the time to reach threshold, this leads to ordinary differential equations that may be easily solved. Several analytical approaches are explored that involve perturbation expansions for large and small values of the noise parameter. For ranges of the parameters appropriate for these asymptotic methods, the perturbation solutions are used to establish the validity of the one-dimensional approximation for both small and large values of the noise parameter. Additional verification is obtained with the excellent agreement between the mean and variance of the firing time found by numerical solution of the differential equations for the one-dimensional approximation and those obtained by simulation of the solutions of the model stochastic differential equations. Such agreement extends to intermediate values of the noise parameter. For the mean time to threshold, we find maxima at small noise values that constitute a form of stochastic resonance. We also investigate the dependence of the mean firing time on the initial values of the voltage and recovery variables when the input current has zero mean.
Year
DOI
Venue
2003
10.1162/089976603321043739
Neural Computation
Keywords
DocType
Volume
differential equation,markov process,partial differential equation,gaussian white noise,ordinary differential equation,stochastic differential equation,stochastic resonance
Journal
15
Issue
ISSN
Citations 
1
0899-7667
4
PageRank 
References 
Authors
0.91
2
3
Name
Order
Citations
PageRank
Henry C. Tuckwell14911.37
Roger Rodriguez2163.00
F.Y.M. Wan3344.07