Long-term potentiation of field excitatory post-synaptic potentials (fEPSP) recorded from the dorsal hippocampus in R26CT and R26CT-CRE mice. A) Summary time course of normalized fEPSP slope values in 3 month old R26CT mice in LTP (black square, (n = 10(10)) and R26CT-CRE (open circle, n = 12(13)), before and after high frequency stimulation (HFS) (3 x 100 Hz/1 s at 20 s intervals) indicated by the arrow at 30 minutes. Insets represent averaged fEPSP sweeps before and after HFS. The vertical bar is 2 mV B) Summary quantification of LTP for R26CT and R26CT-CRE mice at 1, 2, and 3 hrs post-HFS. C, D) Same as panel A and B above except for 8 month old R26CT (black square, (n = 10(10)) and R26CT-CRE (open circle, (n = 12(12)). The values represent the mean ± SEM from n slices. LTP was significantly enhanced in R26CT-CRE mice at 8 months of age (*p < 0.05, **p < 0.01). Significance was determined using an unpaired t-test between genotypes.