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Circuit demonstrating Maedo-Makino type of artificial spiking neuron (brain cell). Model is a simplification of Hodgkin-Huxley model. Circuit is taken from ECE course materials at Cornell University (https://people.ece.cornell.edu/land/PROJECTS/NeuralModels/index.html)
Top circuit is a simple integrate-and-fire neuron. Input current is integrated until threshold (600mV in artificial neuron, -60mV in real neuron) is reached, then neuron fires producing ACTION POTENTIAL (4V in artificial neuron, 100mV in real neuron). Next, neuron is temporarily deactivated and does not react to input - REFRACTORY PERIOD. Input current constantly leaks from the cell membrane driving cell towards RESTING potential (0V in artificial neuron, -75mV in real neuron).
Bottom circuit is a bursting neuron. Instead of sending single spike when activated, neuron is sending several spikes in rapid succession - so called SPIKE TRAIN.
Each neuron circuit consist of sub-circuits each simulating in / out flows of sodium and potassium ions in real neurons.
Demonstration:
HOLD push button to inject input current into one of the neurons. Observe resulting voltage spikes (green and blue lines).
For more details on Maedo-Makino type of neuron circuit look for "A pulse-type hardware neuron model with beating, bursting excitation and plateau potential" paper.
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