The mice were handled daily and received 7 d to recover. (< 0.001) and a significant interaction (= 0.0081). Post hoc Bonferroni's tests showed that both MK-801- and vehicle-treated mice spent significantly more time in the previously MeAM-paired chamber on Day 3 (CPP test) compared with Day 1 baseline level (< 0.001), suggesting that the mice acquired CPP memory. In the vehicle-treated mice, CPP score on Day 6 (retest) was significantly different from that on Day 5 (CPP test) (< 0.01) and is equivalent to the baseline level (> 0.9), suggesting that ANI disrupted reconsolidation of MeAM CPP. In contrast, in the MK-801-treated mice, CPP score on Day 5 was similar to that on Day 6 (> 0.9). These results suggest that destabilization of CPP memory was blocked by MK-801. The infusion cannula tip locations are shown in Figure 1C. Only mice with cannula tips at or within the boundaries of LA and BLA were included in the data analysis. Open in a separate window Figure 1. Effect of NMDAR antagonist on anisomycin-mediated the disruption of MeAM CPP. (= 10) or vehicle (= 10) bilaterally into the amygdala 30 min before the CPP test. ANI (62.5 g/side) was administered bilaterally into the amygdala 60 min after the CPP test. CPP was assessed 24 h after the CPP test (retest). The vehicle control is saline, same as the vehicle control in Figure 2B. Therefore, the data of vehicle control are combined to make number of 10 and reused in Figure 2B. (***) < 0.001 (+)-Clopidogrel hydrogen sulfate (Plavix) vs. retest of the vehicle-ANI group. (##) < 0.01, CPP test vs. retest. (= 4) exhibited higher levels of p-GluR1-Ser845 when compared with the saline-paired mice (= 4). ANI-mediated (= 4) reversal of the increase in p-GluR1-Ser845 in the MeAM-paired mice was prevented in the MK-801-treated mice (= 3). (*) < 0.05, (**) < 0.01 vs. ANI. (#) < 0.05 vs. saline. Phosphorylation of GluR1 at Serine-845 (p-GluR1-Ser845) is important for the trafficking of AMPARs in an activity-dependent manner. Phosphorylated GluR1-Ser845 by cAMP-dependent protein kinase (PKA) increases channel open probability and increases surface expression of AMPARs through recycling the GluR1 pool after their endocytosis (+)-Clopidogrel hydrogen sulfate (Plavix) (Banke et al. 2000; Man et al. 2007). One-way ANOVA showed that there were signi?cant differences among the four groups in the level of p-GluR1-Ser845 (= 0.0029, Rabbit Polyclonal to MYT1 Fig. 1D). MeAM-paired mice (+)-Clopidogrel hydrogen sulfate (Plavix) (= 4) exhibited higher levels of p-GluR1-Ser845 compared with saline-paired mice (= 4) (Bonferroni post hoc analysis, = 0.0441). The level of p-GluR1-Ser845 was reduced by ANI (= 4, = 0.0042, MeAM vs. ANI). Furthermore, the ANI-mediated decrease in p-GluR1-Ser845 was (+)-Clopidogrel hydrogen sulfate (Plavix) reversed after MK-801 treatment (= 3, = 0.0306, MK-801-ANI vs. ANI). Thus, the activation of NMDARs is required for the dephosphorylation of p-GluR1-Ser845. We further determined which subtypes of NMDARs were responsible for MeAM CPP destabilization. The selective NR2A receptor antagonist NVP-AAM077 (NVP, 2.5 g/side, = 11), the NR2B receptor antagonist ifenprodil (IFN, 1 g/side, = 10) or the vehicle (= 10) was infused to the amygdala 30 min before the CPP test. ANI (62.5 g/side) was administered 60 min after the CPP test. CPP was assessed 24 h after the CPP test (retest). A mixed two-way ANOVA revealed main effects of group (IFN vs. vehicle, = 0.0121), days (< 0.001), and a significant interaction (= 0.003) in the IFN treatment (Fig. 2A) but not in the NVP treatment (Fig. 2B) (NVP vs. vehicle, = 0.8726; days, < 0.001; interaction, = 0.4586). In the IFN-treated mice, CPP score in Day 5 was similar to that on Day 6 (> 0.9). In contrast, in the vehicle-treated mice, CPP score on Day 6 (retest) was significantly different from that on Day 5 (CPP test) (< 0.001) and is equivalent to the baseline level (> 0.9). These results suggest that destabilization of CPP memory was blocked by IFN but not by NVP. The infusion cannula tip locations of IFN and NVP are shown in Figure 2C and D, respectively. Open in a separate window Figure 2. Anisomycin-mediated disruption of MeAM CPP is blocked by NR2B-containing but not by NR2A-containing NMDAR antagonist. (= 10), the selective NR2A receptor antagonist NVP-AAM077 (NVP, 2.5 g/side, = 11), or the vehicle (= 10) to the amygdala 30 min before the CPP test. ANI (62.5 g/side) was administered 60 min after the CPP test. CPP was assessed 24 h after the CPP test (retest). (***) < 0.001 vs. retest of the vehicle-ANI group. (= 4) exhibited higher level of p-GluR1-Ser845 when compared with the saline-paired mice (= 4). The level of p-GluR1-Ser845.