Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.
The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds < or =43 kHz while simultaneously saving two channels of data with 16-bit precision. G-clamp also includes utilities for measuring current-voltage relations, synaptic strength, and synaptic gain. Taking an approach built on a commercially available software/hardware platform has resulted in a system that is easy to assemble and upgrade. In addition, the graphical programming structure of LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.
D000703:Analog-Digital Conversion; D000818:Animals; D002478:Cells, Cultured; D003196:Computer Graphics; D003198:Computer Simulation; D003199:Computer Systems / Q000639:trends; D003628:Database Management Systems; D004553:Electric Conductivity; D004594:Electrophysiology / Q000379:methods*; D008564:Membrane Potentials / Q000502:physiology; D008838:Microcomputers; D008959:Models, Neurological; D009431:Neural Conduction; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000295:instrumentation / Q000379:methods*; D012984:Software; D013269:Stochastic Processes; D013569:Synapses; D009435:Synaptic Transmission