Liu J, et al. - The hypothesis that sevoflurane blocks long-term potentiation only if it is present during the high-frequency stimulation that induces long-term potentiation, was tested herein. It was noted that when present during the high-frequency stimulation, sevoflurane blocked long-term potentiation formation. This blockage of long-term potentiation did not persist when sevoflurane was discontinued before the high-frequency stimulation. These findings may explain why short periods of insufficient sevoflurane anesthesia may lead to recall of painful or traumatic events during surgery.