Rate synchronization as a deterministic signal in neural spike trains

We introduce a simple method to analyze recorded spike trains in sensory neurons that allows to reveal deterministic aspects of spiking dynamics. In particular, events with an associated firing rate f(r), are defined whenever two successive spikes on a given cell alpha occur at times t(i)(alpha) and t(i-1)(alpha) such that (f(r) + Deltaf(r))(-1) < \t(i)(alpha)-t(i-1)(alpha)\ < (f(r) - Deltaf(r))(-1) for a given Deltaf(r). We then look for synchronization of those events on different cells. Our results show that synchronized events are sharply correlated with stimuli. The method is used to analyze experimental time series obtained on retinal ganglion cells and synthetic time series. (C) 2004 Elsevier B.V. All rights reserved.