Figure 4.

Effect of intravenous administration of acetaldehyde on the induction of LTP in the dentate gyrus in vivo. (A) Time-course of changes in evoked potentials. Saline or 0.06 g kg⁻¹ acetaldehyde was intravenously administered at time −20 min, and tetanic stimulation (30 pulses at 60 Hz) was applied at time 0. In another group, 0.06 g kg⁻¹ acetaldehyde was intravenously administered at time −20 min, but tetanic stimulation was not applied. The population spike amplitudes and the pEPSP slopes were expressed as the percentage of baseline values immediately before tetanic stimulation (time 0). Insets are representative records of evoked potentials at the times denoted by the numbers. (B) Dose-dependent effect of acetaldehyde. Intact group received tetanic stimulation without intravenous administration. Saline or acetaldehyde (0.04–0.08 g kg⁻¹) was intravenously administered 20 min prior to tetanic stimulation. The average of the population spike amplitudes 30–60 min after tetanic stimulation was calculated as an index of LTP magnitude. All data are the mean±s.e.mean of five rats. ^**P<0.01 vs saline group, Duncan's multiple range test.