Ionophoresis is a means to apply drugs or chemicals to cells using a
micropipette. It basically uses electrical current to drive the charged
substance(s) in the pipette to the bath solution.
The advantage of using ionophoresis is that it is very easy, especially
that you can controlled it using almost any commercial program such as
pClamp. However, the exact concentration of the drug you "spit out" can
be difficult to calibrate.
-- Fred