File:Lu Nicoll 2009 FIG4.jpg

Figure 4.

AMPARs Adjust Rapidly to the Deletion of GluA2 (A) (A1 and A2) The time course for the changes in synaptic transmission in hippocampal slice cultures from GRIA2fl/fl mice after transfection of Cre-IRES-GFP. Ratio of RI (open circles, 3–5 days, 0.95; 6 days, 0.99; 7–8 days, 0.71; 9–10 days, 0.60; 11–12 days, 0.34; 12–14 days, 0.16; >14 days, 0.15), ratio of AMPAR EPSCs (closed circle, 3–5 days, 0.96; 6 days, 0.49; 7–8 days, 0.57; 9–10 days, 0.56; 11–12 days, 0.50; 12–14 days, 0.57; >14 days, 0.51), and ratio of NMDAR EPSCs (closed diamonds, 3–5 days, 1.08; 6 days, 1.01; 7–8 days, 1.06; 9–10 days, 1.04; 11–12 days, 0.99; 12–14 days, 1.01; >14 days, 1.10) from transfected cells to neighboring control cells, respectively. Open square shows RI from CA1 pyramidal neurons from germline GluA2 KO mice (0.13 ± 0.02, n = 5). (A2) Graph shows the percentage of the average AMPAR EPSCs (51.7% ± 5.2%; n = 86; ∗p < 0.0001), NMDAR EPSCs (97.8% ± 13.2%; n = 64; p = 0.81), and RI (15.0% ± 1.8%; n = 19; ∗p < 0.0001) from transfected cells or GluA2 KO cells (13.3% ± 2.0%; n = 5; ∗p < 0.01) to control cells. (B) (B1–B3) Scatter plots (B1) and bar graphs (B2 and B3) show amplitudes of EPSCs for single pairs (open circles) and mean ± SEM (filled circles) for GRIA2fl/fl. (Inset in B1) Sample traces are as follows: black, control; green, Cre. (B2) EPSC amplitudes show a significant reduction in the AMPAR EPSCs (Cnt, −66.2 ± 3.8 pA; Cre, −34.2 ± 2.5 pA; n = 86; ∗p < 0.0001). (B3) There was no change in the NMDAR EPSCs (GluA2, Cnt, 40.0 ± 3.7 pA; Cre, 39.1 ± 3.4 pA, n = 64; p = 0.81). The data were pooled from acute hippocampal slices (P13–P17) from animals injected at P0–P2 and from hippocampal slice cultures. (C and D) Bar graphs show average RI (C) (Cnt, 0.99 ± 0.03, n = 30; ΔGluA2, 0.15 ± 0.02, n = 19; ∗p < 0.001) and average PPR (D) (Cnt, n = 84; ΔGluA2, n = 29; p > 0.05). Left were sample traces. (E) Sample traces of mEPSCs shown at a low gain and sweep speed (traces on left; scale bar, 10 pA, 500 ms) and averaged mEPSCs at a high gain and sweep speed (traces on right). Control trace (black) has been superimposed on the trace from a Cre cell. Scale bar, 5 pA, 10 ms. mEPSCs were recorded from acute hippocampal slices (P13–P18) from animals injected at P0–P2. (F) (F1) Bar graphs show mEPSCs amplitude (Cnt, −10.51 ± 0.37 pA; ΔGluA2, 11.08 ± 0.65 pA; p = 0.42), (F2) frequency (Cnt, 0.28 ± 0.03 Hz; ΔGluA2, 0.16 ± 0.03 Hz; ∗p < 0.001), and (F3) decay (Cnt, 11.30 ± 0.49 ms; ΔGluA2, 9.75 ± 1.14 ms; p = 0.27). n = 22 and 17 for Cnt and ΔGluA2, respectively.