Fig. 9. Tiam1 mediates Rac1 activation through Ca²⁺ signaling in A-stimulated hippocampal cells. Hippocampal neurons were incubated for 4 hours with A_1-42 in the presence of BAPTA-AM (A) or Gö6976 (B) and then the active Rac1 fraction was pulled-down using the PAK-PBD binding domain. The active form of Rac1 was revealed using Rac1 monoclonal antibody. ^**P<0.01.