Rhythmic activity in a simulated neuronal network

Publisher Website
Google Scholar
Abstract
A digital computer has been programmed to simulate a neuronal network consisting ot 80 cells with the following characteristics: AH cells in the network had a set random probability of discharge when not affected by other cells. The probability of discharge was chosen as one system parameter (PD). Subsequent to the firing of any neurone in the network, a certain number of other neurones underwent a change in their probability of discharge, consisting of an inhibitory period followed by a period of increased excitability. The changes of excit?ability mimic the changes of the menbrane potential recorded for spontaneously rhythmically active cells in the animal thalamus. Start?ing the network, a typical transient response appeared, consisting of a burst-like activity. The initial activity was followed, 1st by random fluctuations of the number of active cells, later by periods of spon?taneous rhythmic activity that had several characteristics in common with the type of spontaneous activity seen in the animal thalamus. The parameters which affected the rhythmic activity of the network most strongly were the degree of the post-inhibitory increase of the prob?ability of discharge and the degree of distribution of the inhibition to neighboring cells. The results are compatible with the inhibitory phasing theory advanced by Andersen and Sears (1964) to explain the occurrence of spontaneous rhythmic activity in the animal thalamus. However, before sufficient experimental knowledge is available, it is difficult to establish whether the rhythmic activity in the network is of the same type as that of the animal thalamus. A closer study of the parameters governing the behavior of the simulated network has given indications of some parameters to be more closely investigated in future animal experiments.