Fig. 1.
A: dynamic-clamp setup. The user interacts primarily with the master setup to patch the cell and stimulate with current or conductances (G). The master setup also records the cellular responses for later analysis. The dynamic clamp runs continuously on the slave setup, receiving the membrane potential (Vm) from the amplifier, calculating the currents that flow through the various conductances, and then sending the currents to the command input on the amplifier. The black illustration is a single-electrode dynamic-clamp setup where the membrane potential measurement and current injection are done through the same electrode. The red illustration is for the dual-electrode setup where the cell is patched with 2 electrodes, 1 to read membrane potential and 1 to pass current. A/D, analog-to-digital channels; D/A, digital-to-analog channels; Vrev, reversal potential; IDC, dynamic-clamp current. B: mafDC user interface for invoking dynamic clamp on the slave setup in WaveMetrics IGOR. The panel assists the user to select features of the dynamic clamp (checkboxes) and to enter parameters for controlling them. The text field at the bottom of the panel contains a preview of the command to be executed. The dynamic clamp is invoked by hitting the “Start DC” button. See methods and results for explication of components and parameters.