Article by BCF/RIKEN members published in PLoS Computational Biology

Contemporary theory of spiking neuronal networks is based on the linear response of the integrate-and-fire neuron model derived in the diffusion limit. We find that for non-zero synaptic weights, the response to transient inputs differs qualitatively from this approximation. The response is instantaneous rather than exhibiting low-pass characteristics, non-linearly dependent on the input amplitude, asymmetric for excitation and inhibition, and is promoted by a characteristic level of synaptic background noise. We show that at threshold the probability density of the potential drops to zero within the range of one synaptic weight and explain how this shapes the response. The novel mechanism is exhibited on the network level and is a generic property of pulse-coupled networks of threshold units.

Moritz Helias, Moritz Deger, Stefan Rotter & Markus Diesmann 
Instantaneous Non-Linear Processing by Pulse-Coupled Threshold Units
PLoS Comput Biol 6(9): e1000929 (September 2010)
doi:10.1371/journal.pcbi.1000929

Press release of the University of Freiburg (German)