Figure 6.
Sublethal Aβ1-42 treatment decreased the phosphorylated levels of protein kinases in the MAPK cascade (P-Raf and P-MEK). A, The phosphorylation of Raf was examined by the use of an antibody against phosphorylated Raf-1 (P-Raf). Pretreatment with 5 μm Aβ1-42 for 2 hr attenuated the BDNF-induced increase in P-Raf. B, Quantification of the effects of pretreatment with 5 μm Aβ1-42. Estimates are the mean ± SEM (n = 3) expressed in terms of P-Raf levels induced by BDNF (represented by B). Effects of 5 μm Aβ1-42 (B + A) were significant (*p < 0.05, unpaired Student's t test). C, Pretreatment with 5 μm Aβ1-42 decreased the BDNF-induced elevation in the level of phosphorylated MEK1/2 (P-MEK1/2). D, Quantification of the effects of pretreatment with 5 μm Aβ1-42 on BDNF-induced MEK1/2 phosphorylation. Estimates are the mean ± SEM (n = 3) expressed in terms of P-MEK1/2 levels induced by BDNF. Effects of 5 μm Aβ1-42 (B + A) were significant (*p < 0.05, unpaired Student's t test).