THE CODES OBSERVED IN OSCILLATING NEURAL ASSEMBLIES OF THE OLFACTORY PATHWAY MAY BE REPRODUCED BY A SIMPLE NEURAL NETWORK

Abstract

The electrophysiological data recorded in the glomerular stage of the insect olfactory pathway show both a coherent global oscillating behavior of the neurons of this stage- carrier waveform?-, and a reproducible complex activity pattern- code?- of some of these neurons, in phase with the global oscillation. We propose a possible interpretation of this type of biological activity patterns, using a simple model of the glomerular stage of the insect olfactory pathway that has been previously designed. This model is analytically tractable, even when synaptic noise, random synaptic weights, inputs or delays are taken into account. This model exhibits the property of coding its inputs through spatio-temporal patterns which are the attractors of its dynamics. These attractors can be long cycles, robust against synaptic noise and also to input fluctuations, provided that the latter occur within well-defined limits. We give an example of a set of adapted synaptic weights and inputs leading our model to the attractors corresponding to a given neuronal code, drawn from experimental data.