Voltage Clamp Technique. Various experiments will deal with the several parameters of hodgkin huxley equations and will model resting and action potentials voltage and current clamp pharmacological effects of drugs that block specific channels etc. The voltage clamp is a technique used to control the voltage across the membrane of a small or isopotential area of a nerve cell by an electronic feedback circuit.
Transmembrane voltage is recorded through a voltage electrode relative to ground and a current electrode passes current into the cell. The voltage clamp technique was used by hodgkin and huxley to determine the behavior of the ionic conductances responsible for the generation of the action potential. Under voltage clamp conditions voltage gated ion channels open and close as normal but the voltage clamp apparatus compensates for the changes in the ion current to maintain a constant membrane potential.
Voltage clamp techniques 21 receives a signal from a voltage recording electrode e and compares this with a command potential.
The basic circuit for the squid axon is shown below. The experimenter uses a set of electronic equipment referred to here as a voltage clamp device to hold the membrane voltage at a desired level the command voltage while measuring the current that flows across the cell membrane at that voltage. The basic circuit for the squid axon is shown below. The voltage is normally stepped to a family of levels matching preset command patterns and the current supplied or absorbed by the circuit to hold the voltage at each level is measured.
