ACTION-POTENTIALS RECORDED WITH PATCH-CLAMP AMPLIFIERS - ARE THEY GENUINE

A growing number of experimental studies have used patch-clamp amplifi ers (PCAs) in the current-clamp (CC) mode to investigate classical exc itability. In this paper we show that the measurements obtained in thi s way are affected by errors due to the electronic design of the PCA i nput section. We present experimental evidence of such errors, and dem onstrate that they derive from PCA current absorption. Moreover, we pr opose a new PCA input-circuit configuration for the CC mode, which is suitable for accurately recording physiological voltage signals and is perfectly compatible with the standard voltage-clamp mode.