Abstract
1. The electrical response to inward current pulses were studied in the membrane of a single nerve fiber of the crayfish, Procambarus clarkii, depolarized by KCl.
2. The hyperpolarizing response was observed at a critical membrane potential producing a hump or repetitive and spike-like potential.
3. Cessation of a second inward current pulse during conditioning hyper-polarization caused break-depolarization and, at a critical intensity, a slow depolarizing response.
4. The electrical responses observed in this membrane could be mostly explained in terms of changes of the membrane resistance.
