Stochastic Leaky Integrate-and-Fire Model

τ dV/dt = −(V − V_rest) + RI + σξ(t)

Parameters

τ membrane time constant 20 ms

V_thresh threshold −55 mV

V_rest resting potential −70 mV

I input current 15 pA

σ noise amplitude 5 mV

R membrane resistance 1 MΩ

ISI window 5 s

V(t+dt) = V + (dt/τ)[−(V−V_rest) + RI] + σ√(dt/τ) · N(0,1)

Membrane Potential

Spike Events

Instantaneous Firing Rate

Membrane V

Threshold

Spike

Total Spikes

0.0

Firing Rate (Hz)

—

Mean ISI (ms)

—

CV of ISI

The coefficient of variation (CV) measures spike timing variability. A CV near 1 indicates Poisson-like stochastic firing; CV near 0 indicates regular, clock-like firing.