Fig. 3

Both CP-AMPAR and N-AMPARs contribute to the Aβ-mediated over-scaling of HSP. a1 and b1 Treatment paradigms. mEPSCs were recorded in the presence of PhTx after 8 h (a1) and 24 h (b1) of TTX or TTX/Aβ incubation. a2 and b2 Normalized mEPSC amplitudes after 8h (a2) (control = 12.5 ± 0.42, n = 10; Con → PhTx = 12.1 ± 0.51, n = 10; 8h TTX = 13.9 ± 0.58, n = 8; 8h TTX → PhTx = 12.2 ± 0.72, n = 8; 8 h TTX/Aβ = 13.9 ± 0.63, n = 9; 8 h TTX/Aβ → PhTx = 12.5 ± 0.66; n = 9) and 24 h (b2) HSP (control = 12.1 ± 0.60, n = 9; control → PhTx = 11.7 ± 0.43, n =9; TTX = 16.6 ± 0.59, n = 8; TTX → PhTx = 15.1 ± 0.76, n = 8; TTX/Aβ = 19.9 ± 0.52, n = 9; TTX/Aβ → PhTx = 17.1 ± 0.78; n = 9). PhTx was only applied to the extracellular recording solution at the time of the recording. c Sample traces of mEPSCs after 24 h application of the indicated treatments. d Stacked graph of the relative contributions of N-AMPARs (mEPSC amplitude after application of PhTx) vs. CP-AMPARs (mEPSC amplitude without PhTx − amplitude with PhTx). Application of Aβ caused an increase in both CP-AMPAR and N-AMPAR components in HSP (control CP-AMPAR = 0.01 ± 0.04, n = 7; control N-AMPAR = 0.98 ± 0.05, n = 7; TTX CP-AMPAR = 0.11 ± 0.04, n = 7; TTX N-AMPAR = 1.28 ± 0.06, n = 7; TTX/Aβ CP-AMPAR = 0.18 ± 0.06, n = 6; TTX/Aβ N-AMPAR = 1.44 ± 0.04, n = 6). e Percentage of the CP-AMPAR component after 8 h and 24 h HSP. Ratio = (amplitude without PhTx- amplitude with PhTx)/(amplitude without PhTx) (TTX 0 h = 2.27 ± 1.42%, n = 9; TTX 8 h = 12.14 ± 0.82%, n = 9; TTX 24 h = 13.09 ± 1.99%, n = 8; TTX/Aβ 0 h = 2.52 ± 1.93%, n = 8; TTX/Aβ 8 h = 11.05 ± 2.87%, n = 10; TTX/Aβ 24 h = 18.99 ± 2.13%; n = 10). f Changes in the N-AMPAR current after 8 h and 24 h HSP (TTX 0 h = 1 ± 0.04, n = 9; TTX 8 h = 0.99 ± 0.03, n = 9; TTX 24 h = 1.26 ± 0.03, n = 8; TTX/Aβ 0 h = 1 ± 0.04, n = 10; TTX/Aβ 8 h = 1.02 ± 0.03, n = 10; TTX/Aβ 24 h = 1.46 ± 0.04; n = 10). g Immunostainings of surface GluA1 (red) and GluA2 (green) after 24 h incubation with the indicated treatments. Scale bar represents 2 μm. h Quantification of changes in surface synaptic intensity of GluA1 and GluA2 (GluA1: control = 1 ± 0.03, n = 11; Aβ = 0.88 ± 0.03, n =10; TTX = 1.42 ± 0.03, n = 11; TTX/Aβ = 1.63 ± 0.04, n=11. GluA2: control = 1 ± 0.02, n = 10; Aβ = 0.84 ± 0.04, n =10; TTX = 1.29 ± 0.03, n = 10; TTX/Aβ = 1.39 ± 0.04, n =10). Mann–Whitney U test, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001 ns = not significant