Fig. 5

cGMP elevation through PDE5 inhibition protects against oTau-induced LTP impairment. a Perfusion with compound 7a (50 nM) or sildenafil (50 nM) for 10 min rescued the LTP impairment in oTau-treated slices (7a + oTau: n = 10; sildenafil + oTau: n = 11; oTau: n = 10; ANOVA for repeated measures: F_(1,18) = 20.747, p < 0.0001 and F_(1,19) = 34.688, p < 0.0001 compared with oTau-treated slices, respectively). 7a or sildenafil alone did not modify potentiation (7a: n = 11; sildenafil: n = 11; vehicle: n = 9; F_(1,18) = 0.156, p = 0.697 and F_(1,18) = 0.016, p = 0.900). No significant differences were found between tetanized slices treated with 7a vs. 7a + oTau (F_(1,19) = 0.060, p = 0.809) and between tetanized slices treated with sildenafil vs. sildenafil + oTau (F_(1,20) = 0.013, p = 0.910). b Residual potentiation at 30 and 120 min after tetanus from data shown in C (Vehicle: n = 9 slices/9 animals, 5 males and 4 females; oTau: n = 10 slices/7 animals, 3 males and 4 females; 7a: 11 slices/9 animals, 4 males and 3 females; 7a + oTau: 10 slices/10 animals, 5 males and 5 females; sildenafil: 11 slices/10 animals, 5 males and 5 females; sildenafil + oTau: 11 slices/9 animals, 5 males and 4 females). One-way ANOVA: F_(5,56) = 3.44, p = 0.009 at 30 min and F_(5,56) = 5.673, p < 0.0001 at 120 min. Bonferroni’s: p = 0.04 and p = 0.001 between oTau and vehicle at 30 and 120 min, respectively; p = 0.002 between oTau and 7a + oTau at 120 min; p = 0.03 and p = 0.01 between oTau and sildenafil + oTau at 30 and 120 min, respectively. *p < 0.05, **p < 0.005