Fig. 5

miR124 expression is increased in Aβ-mediated over-scaling due to a decreased EVI1-HDAC1 interaction. a MicroRNAs were purified from rat hippocampal lysates treated for 24 h with the conditions shown and miR124 was quantified by qRT-PCR (Control = 1 ± 0.02, n = 3; Aβ = 1.12 ± 0.02, n =3; TTX = 1.72 ± 0.03, n = 3; TTX/Aβ = 1.97 ± 0.02, n =3). Values normalized to control, error bars = ± SEM. b Hippocampal neurons were transfected with a miR124 BS (containing GFP) or a scrambled BS-GFP for 1 day followed by 24 h treatment with the conditions shown. mEPSC amplitudes were increased in the scrambled BS controls but not in the miR124 BS transfected cells (Control + GFP = 12.33 ± 0.86, n = 3; Aβ + GFP = 10.2 ± 0.97, n =3; TTX + GFP = 16.8 ± 0.62, n = 3; TTX/Aβ + GFP = 19.5 ± 0.74, n =3; Control + BS = 12.9 ± 0.74, n =8; Aβ + BS = 9.9 ± 0.83, n =3; TTX + BS = 11.8 ± 0.86, n =9; TTX/Aβ + BS = 12.9 ± 0.86, n =8; 4 mice per condition). c Co-immunoprecipitation of EVI1 and HDAC1. Using lysates from rat cortical neurons incubated with the conditions shown for 24 h, EVI1 complexes were isolated by immunoprecipitation and probed for HDAC1. EVI1 co-immunoprecipitated with HDAC1 and the association was further decreased by incubation with TTX/Aβ. d Quantification of the co-immunoprecipitation data from C (n = 4); HDAC1 was normalized to the immunoprecipitated EVI1 levels. e MicroRNAs were purified from mouse cortex 24 h after injection of Aβ (10μg) or vehicle control and miR124 was quantified by qRT-PCR (Control = 1.01 ± 0.13, n =10; Aβ = 2.12 ± 0.25, n = 10). Values normalized to control, error bars = ± SEM. f Sample mEPSC traces from recordings in V1 visual cortex for the treatments shown. g Quantification of the traces shown in E. mEPSC amplitudes were increased in the scrambled siRNA controls for VD and VD + Aβ but not in the miR124 siRNA infected cells (no VD + scr siRNA = 11.7 ± 0.52, n = 6; VD + scr siRNA = 14.1 ± 0.23, n =8; VD + Aβ + scr siRNA = 16.1 ± 0..57, n = 5; no VD + miR124 siRNA = 11.4 ± 0.33, n =6; VD + miR124 siRNA = 10.1 ± .62, n = 5; VD + Aβ + miR124 siRNA = 10.3 ± .36, n =6; 4 mice per condition). h Model depicting the disruption of HSP by Aβ. During initiation, both TTX and TTX/Aβ show a normal increase in CP-AMPARs (solid lines), however in the presence of Aβ, CP-AMPAR expression continues to increase subsequently driving a further increase in N-AMPARs and total AMPARs (dashed lines) during the expression phase of HSP. Mann–Whitney U test, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.001, ns = not significant. Values = mean, error bars = ± SEM