# Math Insight

### Applet: Fitzhugh-Nagumo neuron model versus time and phase plane

Illustration of the Fitzhugh-Nagumo spiking neuron model \begin{align*} \diff{v}{t} &= - v(v-a)(v-1) - w + I\\ \diff{w}{t} &= \varepsilon(v-\gamma w) \end{align*} where $v(t)$ is the (normalized) voltage of a neuron at time $t$ and $w(t)$ represents the state of the potassium channels at time $t$.