L.D. Harmon artificial neuron. The first version developed in 1961 is on top and is tracked with orange. More advanced version is at the bottom and is tracked with blue. Although model is simple it allowed Harmon to study 7 different characteristics of the neuron.
Usage:
1) Switch at the top controls excitatory current that drives the neurons.
2) Push buttons inject inhibitory current that can temporarily silence the neurons.
Harmon LD (1961): Studies with artificial neurons, I: Properties and functions of an artificial neuron. Kybernetik Heft 3(Dez.): 89-101.