Action potentials recorded with patch-clamp amplifiers: are they genuine?

A growingnumber of experimental studieshaveusedpatch-clampamplifiers(PCAS) in the currentclamp (CC) mode to investigateclassicalexcitability.In this paperweshowthat the measurements obtained in this way are affectedby errors due to the electronic design of the PCA input section. We present experimental evidence of such errors, and demonstrate that they derive from PCA current absorption. Moreover,wepropose a new PCA input-circuit configuration for the CC mode, which is suitablefor accuratelyrecording physiologicalvoltage signalsand is perfectly compatible with the standard voltage-clamp mode