Single ion channel Recording

Single-Channel Recording

Watch one ion channel switch stochastically between closed and open states. Change the opening and closing rates, membrane voltage, reversal potential, and single-channel conductance, then connect the microscopic current steps to channel kinetics.

Opening rate k_open in s⁻¹ 2.0

Closing rate k_close in s⁻¹ 2.0

Membrane voltage V_m in mV −60

Reversal potential E_rev in mV 0

Single-channel conductance g in pS 30

Open-channel current

−1.80 pA

Measured P_open

0.50

Predicted P_open

0.50

Mean dwell times τ_open / τ_closed

0.50 / 0.50 s

Patch-Clamp Experiment and Channel State

Single-Channel Current Trace

Open and Closed Dwell-Time Distributions

Main ideas In this two-state model, C ⇌ O with P_open = k_open/(k_open + k_close). Mean open and closed dwell times are 1/k_close and 1/k_open. When the channel is open, the current is I = g(V_m − E_rev). Real channels can contain multiple closed, open, and inactivated states; this demo isolates the basic single-channel logic.