 FitzHugh–Nagumo model

The FitzHugh-Nagumo model represents an excitable cell by a fast activation variable and a slower recovery variable. A common nondimensional form is $\dot{V}=V-V^3/3-W+I$, $\dot{W}=\epsilon (V+a-bW)$. Its cubic activation response and recovery feedback can produce an excitable resting state or sustained oscillations through bifurcations. Particular reductions and travelling-wave equations can have additional state variables; their signs and parameter conventions must be stated separately.

The FitzHugh-Nagumo model is a mathematical model used to describe the electrical activity of excitable cells, such as neurons and cardiac cells. It's a simplification of the more complex Hodgkin-Huxley model, which describes action potentials in neurons. The FitzHugh-Nagumo model captures the essential features of excitability and is often used in theoretical biology, neuroscience, and studying various types of wave phenomena in excitable media.