Fig. 5. The effects of amnestic concentrations of sevoflurane (Sev; 0.04 mm) on long-term potentiation. (  A ) Representative traces of field excitatory postsynaptic potentials (fEPSPs) recorded before (  solid trace ) and after (  dashed trace ) the delivery of tetanus stimulation (100 Hz, 1 s). The tetanus stimulation was delivered at time 0 (  arrow ). In control (  filled circle ), the tetanus stimulation (100 Hz, 1 s) consistently induced stable long-term potentiation. Continuous administration of 0.04 mm sevoflurane (  open circle ) throughout the experiments blocked long-term potentiation induction. The tetanus stimulation (100 Hz, 1 s) induced only posttetanic potentiation. (  B ) When sevoflurane at 0.04 mm was applied 10 min after the tetanus stimulation (n = 7), sevoflurane did not affect the maintenance of long-term potentiation (  filled circle ). Data are expressed as mean ± SD. BIC = bicuculline.