FIGURE 5.

AβOs induce down-regulation of synaptophysin protein levels in rat hippocampal cultures and human brain slices. A, down-regulation of synaptophysin mRNA was observed in hippocampal cultures exposed to AβOs (500 nm). qPCR analysis was performed using two different gene normalizers (ACTB and GAPDH). *, p = 0.09; **, p < 0.05, Student's t test. B, synaptophysin (Syp) down-regulation was also detected at the protein level (determined by Western blot analysis) after a 24-h treatment with AβOs (*, p < 0.05 compared with control, indicated by the dashed line). qPCR and Western blot results are presented as means ± S.E. from at least three independent cultures. C, human brain slices were exposed to 500 nm AβOs for 12 h and protein levels (synaptophysin and cyclophilin (Cyc)) were determined by Western blots. Significant down-regulation (*, p < 0.02, Student's t test) of synaptophysin was verified compared with vehicle. Results are means ± S.E. from experiments using material from three independent donors. A representative blot is shown at the top.