Action Potential Dynamics

Action Potential Dynamics is an interactive simulator for exploring how ions, channels, currents, and membrane voltage work together. Watch existing Na⁺, K⁺, and Ca²⁺ particles move through membrane channels while the action potential unfolds on a shared timeline. Drag the time cursor to return to any recorded instant and relate particle motion to channel gates, conductance, current, and voltage. Explore two cell models • Neuron: a compact 0–10 ms Hodgkin–Huxley action potential • Ventricular cell: a 0–500 ms Luo–Rudy I action potential with a calcium-supported plateau Continue through five more labs • Ion channels: use current clamp or voltage clamp with 13 channel types, adjustable pulse lengths, channel controls, and clearly distinguished g, I, Vcmd, and zero-current traces. • Neuronal firing characteristics: compare nine representative neuronal responses and five stimulus protocols. • Cardiac rhythm: follow conduction from the sinus node to the ventricles, then compare normal rhythm with sinus bradycardia, sinus tachycardia, first-degree AV block, and 2:1 second-degree AV block. • Synaptic integration: connect excitatory and inhibitory conductance (gE and gI) to membrane voltage and firing. Compare normal activity with simplified epilepsy-related increased-excitation and reduced-inhibition conditions. • Axon conduction: relate each nodal action-potential peak to the axon diagram, inspect a complete waveform, and compare normal conduction with mild or severe focal demyelination. Current leakage, safety factor, subthreshold depolarization, and conduction failure are shown together. Learn with • A clear membrane-particle view and channel-gate states • Membrane voltage, conductance, and current graphs on one time axis • Equilibrium potentials and channel-opening probabilities • Slow playback and a movable time cursor Pro — one-time purchase • Record conditions and key measurements from all six simulations • Compare the latest two results and export all records as CSV • Run advanced Action Potential experiments with conductance controls and presets • Hold an Ion Channel trace for before-and-after waveform comparison • Unlock five specialized neuron presets in Neuronal Firing and Ion Channels Every diagram, graph, and time cursor is driven by the same model time. Disease-related conditions are simplified comparisons designed to explain mechanisms; they do not reproduce an individual patient’s condition. All simulations run on your device. Action Potential Dynamics is for learning and visualization only. It is not a medical device and is not intended for diagnosis or treatment.