Figure 1.

Baseline synaptic transmission and presynaptic plasticity are normal in aged EC-SOD transgenic mice. The 20-month-old mice were used in the experiments. A, Plots of fEPSP slope versus fiber volley amplitudes. There was no significant difference between aged wild-type (WT) and aged EC-SOD transgenic (EC-SOD TG) mice in baseline synaptic transmission. Error bars indicate SEM for seven determinations. B, Paired-pulse facilitation in aged WT and aged EC-SOD TG mice. Shown are responses to paired pulses in which the fEPSP slope of the response to the second stimulus was expressed as a percentage of the fEPSP slope of the response to the first stimulus plotted against the interpulse interval of the paired pulses. There was no significant difference between aged WT and aged EC-SOD TG mice. Error bars indicate SEM for six determinations. C, Posttetanic potentiation in aged WT and aged EC-SOD TG mice. Shown are points representing 10 responses measured before HFS and 15 responses measured immediately after HFS in the presence of the NMDA receptor antagonist APV (100 μm). There was no significant difference between aged WT and aged EC-SOD TG mice by two-way ANOVA, followed by Bonferroni's post hoc tests. Error bars indicate SEM for five determinations for WT mice and four determinations for EC-SOD TG mice.