Single electrode dynamic clamp with StdpC
Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations. âº A novel implementation of active electrode compensation is introduced for the soft-real time dynamic clamp software StdpC to allow artefact-free dynamic clamp with a single, potentially high impedance, electrode. âº The method and its implementation are tested on an electronic model cell and in two different electrophysiological preparations. âº For the first time, active electrode compensation has been successfully verified with a second, independent electrode both in an electronic substitute cell and in a biological neuron. âº The new method is provided as part of the free software StdpC and comes with semi-automated calibration methods that allow its application by non-expert users.