Voltage Clamp

Breakthroughs in scientific research often rely on the development

of new technologies.  In the case of action potential, detailed

understanding came only after of the invention of the voltage

clamp technique by Kenneth Cole in the 1940s.  This device is

called a voltage clamp because it controls, or clamps, membrane

potential at any level desired by the experimenter.  The basic

principle of voltage clamp and system setup are illustrated as below



Reference

Dale Purves,1997,Neuroscience,Sinauer Associates, Inc., P.53.


Current Clamp
The basic principle of current clamp and system setup are the same

as voltage clamp, the only different is current clamp methods

clamps the current instead voltage, so that in current clamp 

method you can talked that the changes of membrane potential but

not the current flow.


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