The effects of sevoflurane on the field excitatory postsynaptic potential (fEPSP) response during the high-frequency stimulation. Values above 100% indicate tetanic potentiation; values less than 100% indicate tetanic depression. All values are normalized to the fEPSP of the first response in the high-frequency stimulation train of that group (mean ± SD). In all groups, there was significant tetanic potentiation from the second until the tenth stimulus and tetanic depression after the fiftieth stimulus. In the no sevoflurane group (n = 13), sevoflurane is not given at any time during the experiment. In the sevoflurane during group (n = 6), sevoflurane is present 15 min before and 5 min after the high-frequency stimulation. In the sevoflurane before high-frequency stimulation group (sevoflurane before), sevoflurane is present for 20 min and removed 10 min before the high-frequency stimulation (n = 7). There was no significant difference between the groups at any time point.