Action Potential Propagation Simulator

Nerve signals travel as electrical impulses called action potentials — rapid depolarization followed by repolarization that regenerates itself along the length of an axon. This simulator models the axon as a chain of coupled membrane patches: crossing threshold at one point opens voltage-gated channels there, which depolarizes the neighbouring patch enough to trigger it too, so the spike propagates as a self-sustaining wave rather than fading with distance. A colour-coded strip shows the wave moving along the axon in real time while a live trace plots membrane potential at a fixed probe point. Adjust stimulus strength, channel excitability, refractory period and myelination to see how each shapes whether a spike fires at all, how fast it travels, and how closely spikes can follow one another.