Right-left discrimination in a biologically oriented model of the cockroach escape system

We present a biologically oriented model that accounts for left-right discr imination in the cockroach's escape behavior. The model includes the main g roups of neurons found to be involved in the escape response. Each one of t he included neurons is described by the actual processes taking place in an individual neuron (formation of an action potential, transmitter release, conductance changes, etc.). Furthermore, realistic chemical synapses (excit atory or inhibitory and able to undergo different types of modulation) conn ect the various neurons. With this model, we were able to achieve, for a wi de range of inputs representing different wind directions, behavior which r esembles that found experimentally. The model indicates that several synapt ic properties, in particular postsynaptic inhibition and presynaptic facili tation, play a key role in the discrimination of wind direction.