Figure 1

Rescue of D1-induced LTP by DL-AP3 in the Fmr1 KO mice. (A) The pairing training produced a significant, long-lasting potentiation of synaptic responses in Fmr1 WT mice (n = 12 slices/5 mice), but not in Fmr1 KO mice (n = 9 slices/4 mice); (B) DL-AP3 (10 μM) did not alter the amplitude of LTP in Fmr1 WT mice (n = 9 slices/3 mice). DL-AP3 (10 μM) failed to induce LTP in Fmr1 KO mice (n = 11 slices/5 mice). (C) SKF81297 (5μM) facilitated LTP induction in Fmr1 WT mice (n = 8 slices/3 mice), but failed to induce LTP in Fmr1 KO mice (n = 11 slices/5 mice). (D) Bath application of SKF81297 (5 μM) and DL-AP3 (10 μM) induced LTP in Fmr1 WT mice (n = 10 slices/3 mice) (n = 10 slices/3 mice) and markedly rescued the LTP induction by SKF81297 in the Fmr1 KO mice (n = 12 slices/4 mice). (E) SCH23390 (10 μM) blocked the LTP by synergistic application of SKF81297 and DL-AP3 in the KO mice (n = 13 slices/4 mice). (F and G) SKF81297 (5 μM, 30 min) or DL-AP3 (10 μM, 30 min) had no effect on basal synaptic responses without pairing training (n = 8) in the Fmr1 WT and KO mice. (H) Summary of the effects of DL-AP3 or/and SKF81297 on the LTP induction. * p < 0.05, ** p < 0.01 compared with WT; # p < 0.05 compared with control; ^&&p < 0.01 compared with SKF81297 + DL-AP3 in WT mice; ^@p < 0.05 compared with SKF81297 + DL-AP3 in KO mice.