Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Students · Neuroscience Lab

Neuroscience Lab for a heartbeat

Built for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition. Simulate a heartbeat live below — adjust the inputs and watch it respond, right in your browser.

Neuron

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Hodgkin-Huxley NeuronLive

the action potential

Controls

Speed1×

Presets

Injected current (µA/cm²)

The Hodgkin-Huxley model — the Nobel-winning description of the nerve impulse — tracks voltage and the opening of sodium and potassium channels. Below a threshold current the neuron is silent; above it, it fires a train of action potentials whose rate climbs with the stimulus.

▶ Run in Python

Data Inspector

Firing rate0.0 Hz

Regimespiking

ChannelsNa⁺ / K⁺

Governing equation

C_{m} \frac{d V}{d t} = 10 - \overset{g}{ˉ}_{N a} m^{3} h (V - E_{N a}) - \overset{g}{ˉ}_{K} n^{4} (V - E_{K}) - \overset{g}{ˉ}_{L} (V - E_{L})

Reading this result: Above threshold: each stimulus recharges the membrane fast enough to re-trigger Na⁺ channels, so the neuron fires a repetitive train whose rate rises with the current.

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↓

FFT

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Fourier Transform (FFT)Live

decompose a signal into frequencies

Controls

Build a signal from a few sine tones plus noise, and the discrete Fourier transform recovers exactly which frequencies are present — the foundation of all signal processing.

Presets

Tone 1 frequency

Tone 2 frequency

Tone 3 frequency

Noise

▶ Run in Python

Data Inspector

Samples256

Peaks at4, 9

TransformDFT

Governing equation

X_{k} = n = 0 \sum N - 1 x_{n} e^{- 2 π ik n / N} (N = 256, O (N lo g N))

Reading this result: The FFT splits this 2-tone signal into bins: each input sinusoid at 4, 9 appears as a distinct spike, and with noise at 0 the baseline between them stays clean.

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Frequently asked questions

Is this good for students?: Yes — this version of "Neuroscience Lab for a heartbeat" is framed for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.