Electronic circuitry in the form of input and output circuits simulate the functions of neurons of most conceivable types. The input circuit has a signal regulating circuit which automatically reduces or increases its output amplitude, based on prior experience, simulating reverberation and memory neurons, respectively. An output stage has an integrator and a threshold circuit with a possible plurality of different types of inputs applied thereto for generating an output which simulates the responsiveness of a neuron. Different combinations of input and output circuits are used to simulate different types of neurons which can then be assembled into neural networks.