The escape of Tritonia: Dynamics of a neuromuscular control mechanism

A dynamic model is presented, in which co-operative phenomena in populations of neurons are shown to account for the mechanisms that have been observed to control the swimming escape sequence of the mollusk Tritonia.

Abstract

A dynamic model is presented, in which co-operative phenomena in populations of neurons are shown to account for the mechanisms that have been observed to control the swimming escape sequence of the mollusk Tritonia. The system was chosen because of the relatively large amount of information available on its structure and function. The model is based on prior theoretical work on the dynamics of probabilistic neural nets and incorporates the structural and physiological data that have been reported. Dynamic characteristics of the escape sequence, accounted for by the model, include the initiation of the sequence by a single triggering burst, cyclic alternation of activities in the neuron groups controlling dorsal and ventral flexions, and the spontaneous cessation of the sequence. The possible extension of the model to other neuromuscular control mechanisms is discussed.