Izhikevich Model Neurons
Izhikevich neurons are a type of spiking neuron model that can replicate a range of behaviours that neurons exhibit while remaining computationally efficient. For this reason they can be used to model large spiking neural networks while maintaining the biological characteristics of the individual neurons. They are parametrised by just four variables (a,b,c,d), which I've put on the sliders below. Different combinations of these parameters will produce model neurons that behave in different ways, such as the types I've linked to the four buttons (click one!). The final slider is the external current injection to the model brain cell. Between 200 and 800 milliseconds this current is injected into the model cell and the response plotted in the main graph. All of this is being simulated by (probably pretty badly written) javascript in your browser... so yes, this page was basically an excuse to play around with D3 and javascript.
The four parameters: a, b, c and d have different roles. The parameter "a" represents the recovery of the membrane after the spike, the parameter "b" takes into account the sensibility of the neuron to the fluctuation of the voltage, the parameter "c" is used to set the maximum amplitude of the spike after which the neuron's voltage is reset and the parameter "d" determines the after-spike overshoot reset. Read more here.