A simulation study of a neuron in a simple muscle control system.
The mechanism underlying signal transmission through the accessory neuron of the muscle receptor organ in the crayfish abdomen was examined experimentally and by computer simulation. The mathematical model of the accessory neuron and its synaptic inputs was based, in part, on previous neuronal models studied by Stein (1965) and Rall (1964). The model predicted with considerable accuracy the behaviour of the experimental system in a number of situations. It was possible to determine in some detail the mechanisms underlying the frequency response characterized by a threshold and an approximately linearly increasing response for stimulus intensities above threshold. Furthermore, we were able to explain the observation that the accessory cell transforms a regular input train from a stretch receptor into an irregular output train. The highly branched structure of the dendritic tree, combined with a firing threshold in the dendrites which prevents action potentials from invading large parts of the dendritic tree, seems essential in determining these properties.
D000005:Abdomen; D000818:Animals; D003400:Astacoidea; D008465:Mechanoreceptors / Q000502:physiology*; D008959:Models, Neurological; D009435:Synaptic Transmission