electronic model of spontaneous and evoked activity neurons and their analogous connections

ABSTRACT

A spontaneous and evoked generating activity neuron models are designed and constructed, together with their different modes of connections, in order to simulate and study the functions of the real neurons. The study of the designed spontaneous neuron's model shows At a fixed threshold level, the increase of the integrator capacitance value, which equivalent to the real neuron's membrane capacitance, decreases the output firing rate [frequency]. Also, the presynaptic firing rate is greater than that of the postsynaptic one. An inverse relationship is found to be between the firing rate and the level of excitation. In the designed evoked activity neuron's model, the output firing rate is linearly increased by increasing the amplitude of the applied external stimulus. Besides, the frequency of the presynaptic output is greater than that of the postsynaptic one. Different connections between the constructed models were carried out to simulate the function and characteristics of the synapse. In the spontaneous-evoked connection, it was found that the output firing rate of the evoked one was regular as that of the input, but of less firing rate values. When the spontaneous and the evoked neuron's models were connected in parallel and their output acts as an input of an evoked one, the output frequency is found to be irregular and also of less frequency values as in the previous connection