⚡ Passive Membrane Properties Explorer

Visualize how Rm, Cm, and Ra shape the time and length constants of a neuron

Membrane Parameters
Membrane Resistance (Rm) 10000
Ω·cm²
Membrane Capacitance (Cm) 1.0
μF/cm²
Axon Parameters
Axial Resistance (Ra) 100
Ω·cm
Axon Radius (a) 5
μm
Injected Voltage (V0) 20
mV
Derived Constants
Time Constant
—
τ = Rm · Cm
Length Constant
—
λ = √(rm/ra)
Temporal decay: V(t) = V₀ · e−t/τ
Spatial decay: V(x) = V₀ · e−x/λ
λ = √(Rm · a / 2Ra)  ·  unit conversion applied
τ governs how quickly V decays after a current pulse.
λ governs how far a signal spreads along the axon.
At t = τ or x = λ, V falls to ~37% of V₀ (1/e).
Temporal Decay — V(t) = V₀ · e−t/τ
Membrane potential over time after a step current injection at t=0
V(t)
τ marker (37%)
Spatial Decay — V(x) = V₀ · e−x/λ
Membrane potential along the axon from the injection site (x=0)
V(x)
λ marker (37%)