FIGURE 4.

RS 67333-induced reduction of amyloid pathology is prevented by pre-administration of the 5-HT₄ receptor antagonist RS 39604. Two-month-old 5XFAD females were treated with RS 67333 according to protocol 2 (1 mg/kg, twice a week, for 2 months) with or without pre-administration (15 min before) of the 5-HT₄ receptor antagonist RS 39604. (A) Quantification of Aβ₄₂ load in the brain insoluble and soluble fractions. The mean concentration (nanogram per milligram total protein ± SEM, n = 4/group) of Aβ₄₂in the soluble and insoluble fractions from the vehicle-treated group was 0.77 ± 0.10 and 2079.0 ± 203.8, respectively. (B). Representative images of thioflavin T staining in the entorhinal cortex (mosaics, 10× objective). (C) Quantification of plaque number. Data are the mean ± SEM. ^*p < 0.05, ^**p < 0.01 compared with vehicle (unpaired Student’s t test).