Basic LIF model
Simple spike model
A single-compartment leaky integrate-and-fire (LIF) neuron — the simplest useful spike model. Inject current, watch the membrane climb toward threshold, and see when it fires.
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V
−70.0
mV Spikes
0 Resting
Time →
Membrane potential (mV)
What you are seeing
Between spikes the membrane acts like a leaky capacitor: injected current charges it; leak pulls voltage back toward rest (~−70 mV). When V hits threshold, the model fires a spike and resets — a teaching stand-in for action-potential initiation at the axon initial segment.
Clinical detail
Real spikes need fast Na⁺ and delayed K⁺ currents (Hodgkin–Huxley). LIF collapses that into threshold + reset so you can feel rheobase: too little current never spikes; just above threshold you get regular firing. Clinically, AIS channelopathies and some antiepileptics change effective threshold and excitability — the same knobs this demo lets you turn.
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© Omar Garagozov 2026