Fig. 2. Repeated SUS^only treatments at either 1 MHz (HighF) or 286 kHz (LowF) does not reduce plaque burden and amyloid-β levels.

A Plaque burden and morphology appeared similar when comparing sham treated APP23 mice with (B) HighF treated and (C) LowF treated APP23 mice. The Campbell-Switzer silver staining method was used which stains both diffuse and compact plaques equally well. Plaque burden and number of large plaques were analyzed by automated thresholding in ImageJ. (Scale bar: 100 µm). D Plaque burden expressed as % area was not significantly different between the three groups (one-way ANOVA p = 0.16). E There was also no difference in the number of large plaques per mm² of cortex. Cortical tissue was sequentially lysed to generate a detergent-soluble (SDC: sodium deoxycholate) fraction and a detergent-insoluble (GuHCl: guanidine hydrochloride) fraction. F Enzyme-linked immunosorbent assays (ELISAs) for Aβ₄₀ and Aβ₄₂ revealed no difference in detergent-insoluble Aβ₄₂ levels, but (G) the detergent-soluble Aβ₄₂ was higher in the HighF group. H Levels of Aβ₄₀ were not different between the groups in the detergent-insoluble GuHCl fraction, or (I) in the detergent-soluble SDC fraction (I). Violin plots with the median value indicated with a line. J There was no correlation between amyloid-β plaque burden and the number of shocks the mice received on day 5 of the APA retest, and (K) no correlation between amyloid-β plaque burden and the learning index, calculated as the ratio of the number of shocks received on day one day five of the APA retest (Simple linear regression, slopes did not significantly differ from zero, dashed line is 95% confidence intervals).