Fig. 6. Isoflurane-mediated blocking of long-term potentiation induction is reversible. Representative traces of a single experiment are shown before and after long-term potentiation induction in the presence of isoflurane and without isoflurane (A ). Illustration of one experiment, in which field excitatory postsynaptic potentials (fEPSPs) were evoked only in one input. After the application of isoflurane, tetanization failed to induce long-term potentiation. After the removal of isoflurane for 40 min, delivering the same tetanus resulted in robust long-term potentiation. (B ) Summary of six experiments. The arrow indicates the time of tetanic stimulation. Each data point represents the averaged slope of four consecutive fEPSPs normalized to the averaged fEPSP slope before tetanization.